Sulphonium salt initiators

ABSTRACT

Compounds of the formula (I), L, L′, L″, L 1 , L′ 1 , L″ 1 , L 2 , L′ 2 , L″ 2 , L 3 , L′ 3 , L″ 3 , L 4 , L′ 4 , L″ 4 , L 5 , L′ 5 , L″ 5 , L 6 , L′ 6 , L″ 6 , L 7 , L′ 7 , L″ 7 , L 8 , L′ 8  and L″ 8  independently of one another are hydrogen or an organic substituent; and/or one or more of the pairs L 3  and L 5 , L′ 3  and L′ 5  or L″ 3  and L″ 5  together denote a single bond, provided that the respective X, X′ or X″ is not a single bond; and/or L 3  and L 5 , L′ 3  and L′ 5  or L″ 3  and L″ 5  together denote an organic linking group; and/or one or more of the pairs L 1  and L 3 , L 1  and L, L 5  and L 7 , L′ 1  and L′ 3 , L′ 1  and L′, L′ 5  and L′ 7 , L″ 1  and L″ 3 , L″ 1  and L″, or L″ 5  and L″ 7 , together denote an organic linking group; provided that at least one of L, L′, L″, L 1 , L′ 1 , L″ 1 , L 2 , L′ 2 , L″ 2 , L 3 , L′ 3 , L″ 3 , L 4 , L′ 4 , L″ 4 , L 5 , L′ 5 , L″ 5 , L 6 , L′ 6 , L″ 6 , L 7 , L′ 7 , L″ 7 , L 8 , L′ 8  and L″ 8  is other than hydrogen; X, X′ and X″ independently of one another are a single bond, CR a R b  O, S, NR c  or NCOR c ; R a , R b  and R c  independently of one another are hydrogen or an organic substituent; and Y is an inorganic or organic anion; are suitable as photolatent acid generators.

The invention pertains to novel sulphonium salt photoinitiators andtheir use in photocurable compositions.

Sulphonium salts are known in the art as photoinitiators. In GB 2061280triarylsulphonium salts, comprising a phenylythio moiety, are disclosed.Other compounds of this type, inter alia with phenoxy groups, are knownfrom U.S. Pat. No. 4,451,409 and U.S. Pat. No. 4,694,029, for exampletris(4-phenoxyphenyl)sulphonium hexafluorophosphate. WO 03/072567 and WO03/008404 disclose sulphonium salts, wherein the sulphonium ion islocated in a condensed ring system, for example in the thioxanthylmoiety.

One major problem of commercially available sulphonium saltphotoinitiators is the formation of toxic and/or odorous break downproducts like diphenyl sulfide or benzene. In technique there is a needfor effective cationic photoinitiators, which are reactive, inparticular in both clear and pigmented coatings, thin and thick layers,with and without the addition of sensitizers as co-initiators, non toxicand which generate non toxic and odorless break down products and whichfurther are low-yellowing.

It now has been found, that compounds of the formula I,

-   L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄, L″₄,    L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈    independently of one another are hydrogen or an organic substituent;    and/or-   one or more of the pairs L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅    together denote a single bond, provided that the respective X, X′ or    X″ is not a single bond; and/or-   L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅ together denote an organic    linking group; and/or-   one or more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and    L′₃, L′₁ and L′, L′₅ and L′₇, L″₁ and L″₃, L″₁ and L″, or L″₅ and    L″₇, together denote an organic linking group;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇,    L″₇, L₈, L′₈ and L″₈ is other than hydrogen;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b) O, S, NR_(c) or NCOR_(c);-   R_(a), R_(b) and R_(c) independently of one another are hydrogen or    an organic substituent; and-   Y is an inorganic or organic anion; are effective, low-yellowing    photolatent sulphonium salts.

The compounds according to the invention are characterized in that atleast one of the phenyl rings bears a substituent other than hydrogen.

Said compounds excel at a good reactivity in combination with lowyellowing, low odor and good solubility in the photocurable formulation.The photolatent acid sulphonium salt compounds of formula I exhibit avery satisfactory reactivity combined with good solubility and lowyellowing properties. A very important advantage in view ofenvironmental aspects is the fact that the compounds according to thepresent invention do not release benzene.

Preferred are compounds of the formula I, wherein

-   L, L′ and L″ are identical and L₁, L′₁ and L″₁ are identical and L₂,    L′₂ and L″₂ are identical and L₃, L′₃ and L″₃ are identical and L₄,    L′₄ and L″₄ are identical and L₅, L′₅ and L″₅ are identical and L₆,    L′₆ and L″₆ are identical and L₇, L′₇ and L″₇ are identical and L₈,    L′₈ and L″₈ are identical and X, X′ and X″ are identical, namely a    compound of the formula Ia

-   L, L₁, L₂, L₃, L₄, L₅, L₆, L₇ and L₈ independently of one another    are hydrogen, R₁, OR₁, SR₁, NR₁R₂, halogen, NO₂, CN, NR₁COR₂, COOR₁,    OCOR₁, CONR₁R₂, OCOOR₁, OCONR₁R₂, NR₁COOR₂, SO₃H, SO₃M, SOR₁, SO₂R₁    or are COT;    and/or-   one or more of the pairs L₃ and L₅ together are a single bond,    CR_(a)R_(b), CO, O, S, NR_(c) or NCOR_(C); provided that L₃ and L₅    together are no single bond, when the respective X denotes a single    bond; and/or-   one or more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇ together are    C₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O, CR₁═CR₂—S, CR₁═CR₂—NR₁,    CO—O—CO, CONR₁CO, CO-(o-phenylene)-S, CO-(o-phenylene)-S substituted    by one or more D, or are C₁-C₃alkylene interrupted by O, S, NR₁ or    NCOR₁;-   provided that at least one of L, L₁, L₂, L₃, L₄, L₅, L₆, L₇, L₈ is    other than hydrogen;-   T₁ and T₂ independently of one another are hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₅-C₁₂cycloalkenyl, C₆-C₁₄aryl,    C₁-C₂₀alkyl substituted by one or more D, C₂-C₂₀alkyl interrupted by    one or more E, C₂-C₂₀alkyl substituted by one or more D and    interrupted by one or more E, C₅-C₁₂cycloalkyl substituted by one or    more D, C₂-C₁₂cycloalkyl interrupted by one or more E,    C₂-C₁₂cycloalkyl substituted by one or more D and interrupted by one    or more E, C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, C₅-C₁₂cycloalkenyl    substituted by one or more D, C₃-C₁₂cycloalkenyl interrupted by one    or more E, C₃-C₁₂cycloalkenyl substituted by one or more D and    interrupted by one or more E, or C₆-C₁₄aryl substituted by one or    more D;-   R₁, R₂, R₃, R₄, R_(a), R_(b) and R_(c) independently of one another    have the meaning of T₁;-   T denotes T₁ or O-T₂;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   D is hydrogen, R₅, OR₅, SR₅, NR₅R₆, halogen, NO₂, CN, O-glycidyl,    O-vinyl, O-allyl, COR₅, NR₅COR₆, COOR₅, OCOR₅, CONR₅R₆, OCOOR₅,    OCONR₅R₆, NR₅COOR₆, SO₃H or SO₃M;-   E is O, S, COO, OCO, CO, NR₅, NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅,    NR₅COO, SO₂, SO, CR₅═CR₆ or

-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl or    phenyl;-   Y is an inorganic or organic anion; and-   M is an inorganic or organic cation.

C₁-C₂₀alkyl is linear or branched and is, for example, C₁-C₁₈-, C₁-C₁₄-,C₁-C₁₂-, C₁-C₈-, C₁-C₆- or C₁-C₄alkyl. Examples are methyl, ethyl,propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl,hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, octyl, nonyl, decyl,dodecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl and icosyl.

C₁-C₁₈alkyl, C₁-C₁₄alkyl, C₁-C₁₂alkyl, C₁-C₈alkyl, C₁-C₆alkyl andC₁-C₄alkyl have the same meanings as given above for C₁-C₂₀alkyl up tothe corresponding number of C-atoms.

C₂-C₂₀alkyl interrupted by one or more E, with E defined as O, S, COO,OCO, CO, NR₅, NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅, NR₅COO, SO₂, SO,CR₅═CR₆,

is for example interrupted 1-9, 1-7 or once or twice by E. In case thegroups are interrupted by more than one E, said E preferably areseperated from one another by at least one carbon atom, i.e. the Epreferably are non-consecutive, in particular if E denotes O. Examplesare the following structural units —CH₂—O—CH₃, —CH₂CH₂—O—CH₂CH₃,—[CH₂CH₂O]_(y)—CH₃, with y=1-9, —(CH₂CH₂O)₇CH₂CH₃,—CH₂—CH(CH₃)—O—CH₂—CH₂CH₃, —CH₂—CH(CH₃)—O—CH₂CH₃, —CH₂—S—CH₃,—CH₂CH₂—S—CH₂CH₃, —CH₂—(CO)O—CH₃, —CH₂—(CO)—CH₃, —CH₂—NR₅—CH₃,—CH₂CH₂—NR₅—CH₂CH₃, —CH₂—COO—CH₂—CH₂—O—CH₃ etc.

C₂-C₁₀alkenyl is mono or polyunsaturated, linear or branched and is forexample C₂-C₈—, C₂-C₆— or C₂-C₄alkenyl. Examples are allyl, methallyl,vinyl, 1,1-dimethylallyl, 1-butenyl, 3-butenyl, 2-butenyl,1,3-pentadienyl, 5-hexenyl or 7-octenyl, especially allyl or vinyl.

C₅-C₁₂cycloalkyl is for example cyclopentyl, cyclohexyl, cyclooctyl,cyclo-dodecyl, especially cyclopentyl and cyclohexyl, preferablycyclohexyl. C₃-C₁₂Cycloalkyl in the context of the present applicationis to be understood as alkyl which at least comprises one ring. Forexample methyl-cyclopentyl, cyclopentyl, cyclohexyl, methyl- ordimethylcyclohexyl, cyclooctyl, especially cyclopentyl and cyclohexyl,preferably cyclohexyl are also meant. Further examples are structureslike

as well as bridged or fused ring systems, e.g.

etc. are also meant to be covered by the term.

C₂-C₁₂cycloalkyl interrupted by one or more E with E defined as O, S,COO, OCO, CO, NR₅, NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅, NR₅COO, SO₂, SO,CR₅═CR₆,

is for example

C₅-C₁₂cycloalkenyl, has one or more double bonds and is for exampleC₄-C₆-cycloalkenyl or C₆-C₈-cycloalkenyl. Examples are cyclopentenyl,cyclohexenyl or cyclooctenyl, especially cyclopentenyl and cyclohexenyl,preferably cyclohexenyl. C₅-C₁₂cycloalkenyl in the context of thepresent application is to be understood as alkenyl which at leastcomprises one ring. For example methyl-cyclopentenyl,dimethylcyclohexenyl etc. are also meant.

C₆-C₁₄aryl is for example phenyl, 1-naphthyl, 2-naphthyl, anthryl orphenanthryl, in particular phenyl.

Substituted C₆-C₁₄aryl is for example substituted one to four times,e.g. once, twice or three times, especially once or twice. Substituentson the phenyl ring are in position 2-, 3- or 4-, or in position 2,4-,2,6-, 2,3-, 3,4-, 3,5-, 2,4,6—especially in position 2- or 4- of thephenyl ring. Substituted naphthyl, anthryl or phenanthryl is for examplesubstituted one to four times, e.g. once, twice or three times,preferably once.

Glycidyl is

O-glycidyl denotes

O-vinyl is

O-allyl means

Halogen is fluorine, chlorine, bromine or iodine, especially chlorine orfluorine, preferably fluorine.

Phenylene is

o-phenylene means, ortho-phenylene

If L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅ together denote a single bondor an organic linking group, the organic linking group for example isCR_(a)R_(b), CO, O, S, NR_(c) or NCOR_(c), and for example the followingstructural units are formed, provided that L₃ and L₅, L′₃ and L′₅ or L″₃and L″₅ together denote no single bond if the respective X, X′ or X″ isa single bond,

If L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and L′₃, L′₁ and L′, L′₅ and L′₇,L″₁ and L″₃, L″₁ and L″ or L″₅ and L″₇, together denote an organiclinking group; said organic linking group is for example represented byC₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O, CR₁═CR₂—S, CR₁═CR₂—NR₁,CO—O—CO, CONR₁CO, CO-(o-phenylene)-S, CO-(o-phenylene)-S substituted byone or more D, or are C₁-C₃alkylene interrupted by O, S, NR₁ or NCOR₁;and for example the following structural units are formed

Examples for Y as an organic or inorganic anion are halogenide, ClO₄,CN, hydrogenosulfate, trifluoroacetate; or for example non-nucleophilicanions, selected from the group (BZ₄)⁻, (SbZ₆)⁻, (AsZ₆)⁻, (PZ₆)⁻,(B(C₆Z₅)₄)⁻, with Z denoting a halogen, in particular F or Cl,preferably F; C₁-C₂₀alkylsulphonate, C₁-C₂₀haloalkylsulphonate, C₁-C₂₀perfluoroalkylsulphonate, unsubstituted C₆-C₁₀arylsulphonate,camphorsulphonate, C₁-C₂₀-perfluoroalkylsulphonylmethide,C₁-C₂₀-perfluoroalkylsulphonylimide, and C₆-C₁₀arylsulphonatesubstituted by halogen, NO₂, SO₃M, C₁-C₁₂alkyl, C₁-C₁₂haloalkyl,C₁-C₁₂alkoxy, phenylsulphonyloxy, C₁-C₄alkylphenylsulphonyloxy or byCOOR₁₀₀; wherein R₁₀₀ is C₁-C₂₀alkyl, phenyl, benzyl; or phenyl mono- orpoly-substituted by C₁-C₁₂alkyl, C₁-C₁₂alkoxy or by halogen and M is asdefined above.

C₁-C₂₀Alkylsulphonate is R_(x)SO₃ ⁻ wherein R_(x) is linear or branchedC₁-C₂₀alkyl as described above. Examples thereof includemethylsulphonate, ethylsulphonate, propylsulphonate, pentylsulphonateand hexylsulphonate.

C₂-C₂₀Haloalkylsulphonate is R_(x)SO₃ ⁻ wherein R_(x) ishalo-substituted C₂-C₂₀alkyl, C₂-C₁₀-, C₂-C₈— or C₄-C₈-alkyl. Examplesthereof include C₂F₅SO₃ ⁻, C₄F₉SO₃ ⁻ and C₈F₁₇SO₃ ⁻.

C₆-C₁₀Arylsulphonate is R_(x)SO₃ ⁻ wherein R_(x) is C₆-C₁₀aryl, e.g.phenyl or naphthyl.

Alkyl-substituted arylsulphonates are, for example, toluenesulphonate,2,4,6-trimethylbenzene-sulphonate,2,4,6-tris(isopropyl)benzenesulphonate, 4-tert-butylbenzenesulphonateand 4-dodecylbenzenesulphonate.

Halo-substituted arylsulphonates are, for example,4-chlorobenzenesulphonate, 4-fluorobenzenesulphonate,2,4,6-trifluorobenzenesulphonate and pentafluorobenzenesulphonate.

Camphorsulphonate is

C₁-C₂₀-Perfluoroalkylsulphonylmethide is

C₁-C₂₀-perfluoroalkylsulphonylimide is

wherein R_(d), R_(e) and R_(f) independently of one another are C₁-C₂₀perfluoroalkyl which is unsubstituted or is substituted byN(R_(g))(R_(h)), or R_(d), R_(e) and R_(f) are phenyl substituted byCF₃; or R_(d) and R_(e) together are C₁-C₆-perfluoroalkylene, whichoptionally is interrupted by —O—; R_(g) and R_(h) independently of oneanother are C₁-C₁₂alkyl or R_(g) and R_(h) together are C₁-C₆perfluoroalkylene, which optionally is interrupted by O orN(C₁-C₁₂-Alkyl).

Perfluoroalkyl is alkyl which is fully substituted by fluoro, i.e. thehydrogen atoms of the alkyl radical are replaced by fluoro. The sameapplies for the perfluoroalkylene.

Examples of such anions are (C₂F₅SO₂)₂N⁻, (C₄F₉SO₂)₂N⁻, (C₈F₁₇SO₂)₃C⁻,(CF₃SO₂)₃C⁻, (CF₃SO₂)₂N⁻, (C₄F₉SO₂)₃C⁻, (CF₃SO₂)₂(C₄F₉SO₂)C⁻,(CF₃SO₂)(C₄F₉SO₂)N⁻, [(3,5-bis(CF₃)—(C₆H₃)SO₂]₂N⁻,

C₆F₅SO₂C⁻(SO₂CF₃)₂, C₆F₅SO₂N⁻SO₂CF₃. Such anions are known the personskilled in the art. The anions as well as their preparation aredescribed e.g. in U.S. Pat. No. 5,554,664.

Y as organic or inorganic anion, for example is halogen or anon-nucleophilic anion, selected from the group C_(f)F_(2f+1)SO₃ ⁻,(BZ₄)⁻, (SbZ₆)⁻, (AsZ₆)⁻, (PZ₆)⁻ and (B(C₆Z₅)₄)⁻; wherein

Z is a halogen; and f is an integer from 1 to 8.

Y in particular is halogen or a non-nucleophilic anion, selected fromthe group C_(f)F_(2f+1)SO₃ ⁻, (BF₄)⁻, (SbF₆)⁻, (AsF₆)⁻, (PF₆)⁻ and(B(C₆F₅)₄)⁻; wherein f is an integer from 1 to 8.

M as an organic or inorganic cation, for example is Li, Na, K, Cs,N(R_(a))₄, N(R_(a))₃R_(b), N(R_(a))₂R_(b)R_(c), P(R_(a))₄,P(R_(a))₃R_(b), P(R_(a))₂R_(b)R_(c), S(R_(a))₃, S(R_(a))₂R_(b) orSR_(a)R_(b)R_(c).

M preferably is Li, Na, K, N(R_(a))₄, N(R_(a))₃R_(b),N(R_(a))₂R_(b)R_(c), S(R_(a))₃, S(R_(a))₂R_(b), SR_(a)R_(b)R_(c); inparticular Na, K, N(R_(a))₄, N(R_(a))₃R_(b), S(R_(a))₃ orS(R_(a))₂R_(b).

The terms “and/or” or “or/and” in the present context are meant toexpress that not only one of the defined alternatives (substituents) maybe present, but also several of the defined alternatives (substituents)together, namely mixtures of different alternatives (substituents).

The term “at least” is meant to define one or more than one, for exampleone or two or three, preferably one or two.

The term “optionally substituted” means that the radical to which itrefers is either unsubstituted or substituted.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integers or steps.

Interesting are compounds of the formula I and Ia as defined above,wherein L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ andL″₄ independently of one another are hydrogen, R₁, OR₁, SR₁, halogen,NO₂, CN, NR₁COR₂, COOR₁, OCOR₁, CONR₁R₂, OCOOR₁, OCONR₁R₂, NR₁COOR₂,SO₃H, SO₃M, SOR₁, SO₂R₁ or COT;

-   L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈    independently of one another are hydrogen, R₁, OR₁, SR₁, halogen;    and/or-   one or more of the pairs L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅    together are a single bond, CR_(a)R_(b), CO, O, S, NR_(c) or    NCOR_(c); provided that L₃ and L₅, L′₃ and L′₅, L″₃ and L″₅ together    are no single bond, when the respective X, X′ or X″ denotes a single    bond; and/or-   one or more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and    L′₃, L′₁ and L′, L′₅ and L′₇, L″₁ and L″₃, L″₁ and L″ or L″₅ and    L″₇, together are C₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O,    CR₁═CR₂—S, CR₁═CR₂—NR₁, CO—O—CO, CONR₁CO, CO-(o-phenylene)-S,    CO-(o-phenylene)-S substituted by one or more D, or are    C₁-C₃alkylene interrupted by O, S, NR₁ or NCOR₁;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇,    L″₇, L₈, L′₈, L″₈ is other than hydrogen;-   T₁ and T₂ independently of one another are hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted    by one or more D, C₂-C₂₀alkyl interrupted by one or more E,    C₂-C₂₀alkyl substituted by one or more D and interrupted by one or    more E, C₅-C₁₂cycloalkyl substituted by one or more D,    C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkyl    substituted by one or more D and interrupted by one or more E,    C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, or C₆-C₁₄aryl substituted    by one or more D;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   R₁, R₂, R₃, R₄, R_(a), R_(b) and R_(c) independently of one another    have the meaning of T₁;-   T is T, or O-T₂;-   D is hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl,    O-allyl, COR₅, NR₅COR₆, COOR₅, OCOR₅, CONR₅R₆, OCOOR₅, OCONR₅R₆,    NR₅COOR₆, SO₃H or SO₃M;-   E is O, S, COO, OCO, CO, NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅, NR₅COO,    SO₂ or SO, CR₅═CR₆;-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl,    phenyl;-   Y is an inorganic or organic anion; and-   M is an inorganic or organic cation.

Interesting are compounds of the formula I and Ia as defined above,wherein L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ andL″₄ independently of one another are hydrogen, R₁, OR₁, SR₁, halogen,NO₂, CN, COOR₁, SO₃H, SO₃M, SOR₁, SO₂R₁ or COT;

-   L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈    independently of one another are hydrogen, R₁, OR₁, halogen; and/or-   one or more of the pairs L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅    together are a single bond, CR_(a)R_(b), CO, O or S; provided that    L₃ and L₅, L′₃ and L′₅, L″₃ and L″₅ together are no single bond,    when the respective X, X′ or X″ denotes a single bond; and/or-   one or more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and    L′₃, L′₁ and L′, L′₅ and L′₇, L″₁ and L″₃, L″₁ and L″ or L″₅ and    L″₇, together are C₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O,    CR₁═CR₂—S, CR₁═CR₂—NR₁, CO—O—CO, CONR₁CO, CO-(o-phenylene)-S or    CO-(o-phenylene)-S substituted by one or more D;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇,    L″₇, L₈, L′₈, L″₈ is other than hydrogen;-   T₁ and T₂ are independently of one another hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted    by one or more D, C₂-C₂₀alkyl interrupted by one or more E,    C₂-C₂₀alkyl substituted by one or more D and interrupted by one or    more E, C₅-C₁₂cycloalkyl substituted by one or more D,    C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkyl    substituted by one or more D and interrupted by one or more E,    C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, C₆-C₁₄aryl substituted by    one or more D;-   R₁, R₂, R₃, R₄, R_(a), R_(b) and R_(c) independently of one another    have the meaning of T₁;-   T is T₁ or O-T₂;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   D is hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl,    O-allyl, COR₅, COOR₅, OCOR₅, SO₃H or SO₃M;-   E is O, S, COO, OCO, CO, SO₂, SO or CR₅═CR₆;-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl or    phenyl;-   Y is an inorganic or organic anion; and-   M is an inorganic or organic cation;

Interesting are compounds of the formula I and Ia as defined above,wherein L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ andL″₄ independently of one another are hydrogen, R₁, OR₁, halogen, NO₂,CN, COOR₁, SO₃H, SO₃M, SOR₁, SO₂R₁ or COT;

-   L₅, L′₅, L″₅, L₆, L′₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈    independently of one another are hydrogen, R₁ or OR₁; and/or-   one or more of the pairs L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅    together are a single bond, CR_(a)R_(b), CO, O or S; provided that    L₃ and L₅, L′₃ and L′₅, L″₃ and L″₅ together are no single bond,    when the respective X, X′, X″ denotes a single bond; and/or-   one or more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and    L′₃, L′₁ and L′, L′₅ and L′₇, L″₁ and L″₃, L″₁ and L″ or L″₅ and    L″₇, together are C₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O,    CR₁═CR₂—S, CR₁═CR₂—NR₁, CO—O—CO, CONR₁CO, CO-(o-phenylene)-S or    CO-(o-phenylene)-S substituted by one or more D;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅, L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇,    L″₇, L₈, L′₈, L″₈ is other than hydrogen;-   T₁ and T₂ are independently of one another hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted    by one or more D, C₂-C₂₀alkyl interrupted by one or more E,    C₂-C₂₀alkyl substituted by one or more D and interrupted by one or    more E, C₅-C₁₂cycloalkyl substituted by one or more D,    C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkyl    substituted by one or more D and interrupted by one or more E,    C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, or C₆-C₁₄aryl substituted    by one or more D;-   R₁, R₂, R₃, R₄, R_(a), R_(b) and R_(c) independently of one another    have the meaning of T₁;-   T is T₁ or O-T₂;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   D is hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl,    O-allyl, COR₅, COOR₅ or OCOR₅;-   E is O, S, COO, OCO, CO or CR₅═CR₆;-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl or    phenyl;-   Y is an inorganic or organic anion; and-   M is an inorganic or organic cation.

Interesting further are compounds of the formula Ia, wherein

-   L, L₁, L₂, L₃, and L₄ independently of one another are hydrogen, R₁,    OR₁, halogen, SO₃H, SO₃M, SOR₁, SO₂R₁, CN, NO₂ or COT;-   L₅, L₆, L₇ and L₈ independently of one another are hydrogen, R₁ or    OR₁;-   provided that at least one of L, L₁, L₂, L₃, L₄ is SO₃H, SO₃M,    SO₂R₁, CN, NO₂ or COT;-   T₁ and T₂ independently of one another are hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted    by one or more D, C₂-C₂₀alkyl interrupted by one or more E,    C₂-C₂₀alkyl substituted by one or more D and interrupted by one or    more E, C₅-C₁₂cycloalkyl substituted by one or more D,    C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkyl    substituted by one or more D and interrupted by one or more E,    C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, C₆-C₁₄aryl substituted by    one or more D;-   R₁, R_(a), R_(b) and R_(c) independently of one another have the    meaning of T₁;-   T is T₁ or O-T₂;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   D is hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl,    O-allyl, COR₅, COOR₅ or OCOR₅;-   E is O, S, COO, OCO, CO or CR₅═CR₆;-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl or    phenyl;-   Y is an inorganic or organic anion; and-   M is an inorganic or organic cation.

Further interesting are compounds of the formula I or Ia, wherein

-   L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ and L″4    independently of one another are hydrogen, R₁, OR₁, NO₂ or COT;-   L₅, L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈    independently of one another are hydrogen, R₁ or OR₁;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄ is NO₂ or COT;-   T₁ and T₂ are independently of one another hydrogen, C₁-C₂₀alkyl,    C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted    by one or more D, C₂-C₂₀alkyl interrupted by one or more E,    C₂-C₂₀alkyl substituted by one or more D and interrupted by one or    more E, C₅-C₁₂cycloalkyl substituted by one or more D,    C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkyl    substituted by one or more D and interrupted by one or more E,    C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl    interrupted by one or more E, C₃-C₂₀alkenyl substituted by one or    more D and interrupted by one or more E, or C₆-C₁₄aryl substituted    by one or more D;-   R₁, R_(a), R_(b), R_(c) independently of one another have the    meaning of T₁;-   T is T₁ or O-T₂;-   X, X′ and X″ independently of one another are a single bond,    CR_(a)R_(b), O, S, NR_(c) or NCOR_(c);-   D is hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl,    O-allyl, COR₅, COOR₅, or OCOR₅;-   E is O, S, COO, OCO, CO, or CR₅═CR₆;-   R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl,    phenyl; and-   Y is an inorganic or organic anion.

Most interesting are symmetrical compounds of the formula I, that iscompounds of the formula I, wherein L, L′ and L″ are identical and L₁,L′₁ and L″₁ are identical and L₂, L′₂ and L″₂ are identical and L₃, L′₃and L″₃ are identical and L₄, L′₄ and L″₄ are identical and L₅, L′₅ andL″₅ are identical and L₆, L″₆ and L″₆ are identical and L₇, L′₇ and L″₇are identical and L₈, L′₈ and L″₈ are identical and X, X′ and X″ areidentical, namely compounds of the formula Ia

L, L₁, L₂, L₃, L₄, L₅, L₆, L₇, L₈, X and Y are as defined above.

Another embodiment of the invention is a compound of the formula Ia,wherein

-   L, L₁, L₂, L₃ and L₄ independently of one another are hydrogen, NO₂,    R₁, OR₁ or COT;-   L₅, L₆, L₇ and L₈ independently of one another are hydrogen, R₁ or    OR₁;-   provided that at least one of L, L₁, L₂, L₃, L₄ is NO₂ or COT;-   T₁ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl,    C₆-C₁₄aryl substituted by one or more C₁-C₄alkyl, halogen or    C₁-C₄alkoxy;-   T is T₁ or O-T₂;-   T₂ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl,    C₁-C₂₀alkyl substituted by one or more D, C₂-C₂₀alkyl interrupted by    one or more E, C₂-C₂₀alkyl substituted by one or more D and    interrupted by one or more E, C₅-C₁₂cycloalkyl substituted by one or    more D, C₂-C₁₂cycloalkyl interrupted by one or more E,    C₂-C₁₂cycloalkyl substituted by one or more D and interrupted by one    or more E, or C₆-C₁₄aryl substituted by one or more D;-   X is O or S;-   D is hydrogen, R₅, OR₅, halogen, O-glycidyl, O-vinyl, O-allyl, COR₅,    COOR₅ or OCOR₅;-   E is O, COO, OCO or CO;-   R₁, R₂, R₅ and R₆ independently of one another are hydrogen,    C₁-C₁₂alkyl or phenyl; and-   Y is an inorganic or organic anion.

Preferred are compounds of the formula Ia, wherein

-   L, L₁, L₂, L₃ and L₄, independently of one another are hydrogen, R₁,    OR₁ or COT;-   L₅, L₆, L₇ and L₈ are hydrogen; provided that at least one of L, L₁,    L₂, L₃, L₄ is COT;-   T₁ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl, or is    C₆-C₁₄aryl substituted by one or more C₁-C₄ alkyl, halogen or C₁-C₄    alkoxy;-   T is T₁ or O-T₂;-   T₂ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl,    C₁-C₂₀alkyl substituted by one or more O-glycidyl, O-vinyl, O-allyl,    R₅, OR₅, COOR₅ and/or optionally interrupted by one or more O,    C₂-C₁₂cycloalkyl interrupted by one or more O, or is C₆-C₁₄aryl    substituted by one or more C₁-C₄alkyl, halogen or C₁-C₄alkoxy;-   X is O or S;-   R₁ and R₅ independently of one another are hydrogen, C₁-C₁₂alkyl or    phenyl; and-   Y is an inorganic or organic anion.

Further preferred are compounds of the formula Ia, wherein

-   L, L₁, L₂, L₃ and L₄, independently of one another are hydrogen or    COT;-   L₅, L₆, L₇ and L₈ are hydrogen; provided that at least one of L, L₁,    L₂, L₃, L₄ is COT;-   T₁ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl, or is    C₆-C₁₄aryl substituted by one or more C₁-C₄ alkyl, halogen or C₁-C₄    alkoxy;-   T is T₁ or O-T₂;-   T₂ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl,    C₁-C₂₀alkyl substituted by one or more O-glycidyl, O-vinyl, O-allyl,    R₅, OR₅, COOR₅ and/or optionally interrupted by one or more O,    C₂-C₁₂cycloalkyl interrupted by one or more O, or is C₆-C₁₄aryl    substituted by one or more C₁-C₄ alkyl, halogen or C₁-C₄ alkoxy;-   X is O or S;-   R₅ is hydrogen, C₁-C₁₂alkyl or phenyl; and-   Y is an inorganic or organic anion.

Other interesting compounds according to the invention are compounds ofthe formula I wherein

-   L, L₁, L₂, L₃ and L₄, independently of one another are hydrogen or    COT;-   L₅, L₆, L₇ and L₈ are hydrogen; provided that at least one of L, L₁,    L₂, L₃, L₄ is COT;-   T₁ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl, or is    C₆-C₁₄aryl substituted by one or more C₁-C₄alkyl, halogen or    C₁-C₄alkoxy;-   T is T₁ or O-T₂;-   T₂ is hydrogen, C₁-C₂₀alkyl, or is C₁-C₂₀alkyl substituted by one or    more R₅, OR₅ or COOR₅ and/or optionally interrupted by one or more    O;-   X is O or S;-   R₅ is hydrogen, C₁-C₁₂alkyl or phenyl; and-   Y is a halogen or a non-nucleophilic anion, selected from the group    C₁-C₂₀-perfluoroalkylsulphonylmethide, C_(f)F_(2f+1)SO₃ ⁻, (BZ₄)⁻,    (SbZ₆)⁻, (AsZ₆)⁻, (PZ₆)⁻ and (B(C₆Z₅)₄)⁻;-   Z is a halogen; and-   f is an integer from 1 to 8.

Another embodiment of the invention are compounds of the formula I,wherein

-   L is COT;-   L₁, L₂, L₃, L₄, L₅, L₆, L₇ and L₈ are hydrogen;-   T₁ is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl, or is    C₆-C₁₄aryl substituted by one or more C₁-C₄ alkyl, halogen or C₁-C₄    alkoxy;-   T is T₁ or O-T₂;-   T₂ is hydrogen, C₁-C₂₀alkyl, or is C₁-C₂₀alkyl substituted by one or    more OR₅, COOR₅ and/or optionally interrupted by one or more O;-   X is O or S;-   R₅ is hydrogen, C₁-C₁₂alkyl or phenyl;-   Y is a halogen or a non-nucleophilic anion, selected from the group    C_(f)F_(2f+1)SO₃ ⁻, C₁-C₂₀-perfluoroalkylsulphonylmethide, (BF₄)—,    (SbF₆)—, (AsF₆)—, (PF₆)—, (B(C₆F₅)₄)—; and-   f is an integer from 1 to 8.

L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ and L″₄independently of one another are hydrogen, R₁, OR₁, SR₁, halogen, NO₂,CN, COR₁, NR₁COR₂, COOR₁, OCOR₁, CONR₁R₂, OCOOR₁, OCONR₁R₂, NR₁COOR₂,SO₃H, SO₃M, SOR₁, SO₂R₁ or COT; or for example independently of oneanother are hydrogen, R₁, OR₁, SR₁, halogen, NO₂, CN, COR₁, COOR₁, SO₃H,SO₃M, SOR₁, SO₂R₁ or COT; or e.g. independently of one another arehydrogen, R₁, OR₁, halogen, NO₂, CN, COR₁, COOR₁, SO₃H, SO₃M, SOR₁,SO₂R₁ or COT; in particular L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃,L′₃, L″₃, L₄, L′₄ and L″₄ independently of one another are hydrogen, R₁,OR₁, halogen, SO₃H, SO₃M, SOR₁, SO₂R₁, CN, NO₂ or COT; or for example L,L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄ and L″₄independently of one another are hydrogen, R₁, OR₁, NO₂ or COT;especially L, L₁, L₂, L₃ and L₄ independently of one another arehydrogen, NO₂, R₁, OR₁ or COT; preferably L, L₁, L₂, L₃ and L₄,independently of one another are hydrogen, R₁, OR₁ or COT; especially L,L₁, L₂, L₃ and L₄, independently of one another are hydrogen or COT.

L₅, L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈ independentlyof one another are hydrogen, R₁, OR₁, SR₁, halogen, NO₂, CN, COR₁,NR₁COR₂, COOR₁, OCOR₁, CONR₁R₂, OCOOR₁, OCONR₁R₂, NR₁COOR₂, SO₃H, SO₃M,SOR₁, SO₂R₁ or COT (weil ja im ersten claim L5-L8 wie L1 ist); or forexample independently of one another are hydrogen, R₁, OR₁, SR₁,halogen, O-glycidyl, O-vinyl or O-allyl; and/or one or more of the pairsL₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅ together are a single bond,CR_(a)R_(b), CO, O, S, NR_(c) or NCOR_(c); provided that L₃ and L₅, L′₃and L′₅, L″₃ and L″₅ together are no single bond, when the respective X,X′ or X″ denotes a single bond; and/or one or more of the pairs L₁ andL₃, L₁ and L, L₅ and L₇, L′₁ and L′₃, L′₁ and L₁, L′₅ and L′₇, L″₁ andL″₃, L″₁ and L′ or L″₅ and L″₇, together are C₃-C₄alkylene,CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O, CR₁═CR₂—S, CR₁═CR₂—NR₁, CO—O—CO, CONR₁CO,CO-(o-phenylene)-S, CO-(o-phenylene)-S substituted by one or more D, orare C₁-C₃alkylene interrupted by O, S, NR₁ or NCOR₁;

-   or for example one or more of the pairs L₃ and L₅, L′₃ and L′₅ or    L″₃ and L″₅ together are a single bond, CR_(a)R_(b), CO, O or S.

In particular L₅, L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈ and L″₈independently of one another are hydrogen, R₁ or OR₁; and/or

-   one or more of the pairs L₃ and L₅, L′₃ and L′₅ or L″₃ and L″₅    together are a single bond, CR_(a)R_(b), CO, O or S; provided that    L₃ and L₅, L′₃ and L′₅, L″₃ and L″₅ together are no single bond,    when the respective X, X′, X″ denotes a single bond; and/or one or    more of the pairs L₁ and L₃, L₁ and L, L₅ and L₇, L′₁ and L′₃, L′₁    and L′, L′₅ and L′₇, L″₁ and L″₃, L″₁ and L″ or L″₅ and L″₇,    together are C₃-C₄alkylene, CR₁═CR₂—CR₃═CR₄, CR₁═CR₂—O, CR₁═CR₂—S,    CR₁═CR₂—NR₁, CO—O—CO, CONR₁CO, CO-(o-phenylene)-S or    CO-(o-phenylene)-S substituted by one or more D;-   provided that at least one of L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂,    L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅, L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇,    L″₇, L₈, L′₈, L″₈ is other than hydrogen;-   or for example provided that at least one of L, L′, L″, L₁, L′₁,    L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄, L″₄ is SO₃H, SO₃M, SO₂R₁,    CN, NO₂ or COT, in particular NO₂ or COT.

Preferably L₅, L₆, L₇ and L₈ independently of one another are hydrogen,R₁ or OR₁, in particular hydrogen, provided that at least one of L, L₁,L₂, L₃, L₄ is NO₂ or COT, in particular COT.

In particular preferred L is COT; and L₁, L₂, L₃, L₄, L₅, L₆, L₇ and L₈are hydrogen.

D is for example hydrogen, R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl,O-vinyl, O-allyl, COR₅, NR₅COR₆, COOR₅, OCOR₅, CONR₅R₆, OCOOR₅,OCONR₅R₆, NR₅COOR₆, SO₃H or SO₃M; especially D is hydrogen, R₅, OR₅,SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl, O-allyl, COR₅, COOR₅ orOCOR₅; and preferably D is hydrogen, R₅, OR₅, halogen, O-glycidyl,O-vinyl, O-allyl, COR₅, COOR₅ or OCOR₅.

E is for example O, S, COO, OCO, CO, NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅,NR₅COO, SO₂ or SO, CR₅═CR₆; or E is O, S, COO, OCO, CO, SO₂, SO orCR₅═CR₆; especially E is O, S, COO, OCO, CO or CR₅═CR₆; in particular Eis O, COO, OCO or CO.

T₁ and T₂ for example independently of one another are hydrogen,C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkylsubstituted by one or more D, C₂-C₂₀alkyl interrupted by one or more E,C₂-C₂₀alkyl substituted by one or more D and interrupted by one or moreE, C₅-C₁₂cycloalkyl substituted by one or more D, C₂-C₁₂cycloalkylinterrupted by one or more E, C₂-C₁₂cycloalkyl substituted by one ormore D and interrupted by one or more E, C₂-C₂₀alkenyl substituted byone or more D, C₃-C₂₀alkenyl interrupted by one or more E, C₃-C₂₀alkenylsubstituted by one or more D and interrupted by one or more E, orC₆-C₁₄aryl substituted by one or more D.

T₁ especially is hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl orC₆-C₁₄aryl substituted by one or more C₁-C₄alkyl, halogen orC₁-C₄alkoxy.

T₂ is for example hydrogen, C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl,C₁-C₂₀alkyl substituted by one or more D, C₂-C₂₀alkyl interrupted by oneor more E, C₂-C₂₀alkyl substituted by one or more D and interrupted byone or more E, C₅-C₁₂cycloalkyl substituted by one or more D,C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkylsubstituted by one or more D and interrupted by one or more E, orC₆-C₁₄aryl substituted by one or more D; preferably T₂ is hydrogen,C₁-C₂₀alkyl, C₅-C₁₂cycloalkyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted byone or more O-glycidyl, O-vinyl, O-allyl, R₅, OR₅, COOR₅ and/oroptionally interrupted by one or more O, C₂-C₁₂cycloalkyl interrupted byone or more O, or is C₆-C₁₄aryl substituted by one or more C₁-C₄alkyl,halogen or C₁-C₄alkoxy; In particular T₂ is hydrogen, C₁-C₂₀alkyl, or isC₁-C₂₀alkyl substituted by one or more R₅, OR₅ or COOR₅ and/oroptionally interrupted by one or more 0; especially preferred is T₂ ashydrogen, C₁-C₂₀alkyl, or is C₁-C₂₀alkyl substituted by one or more OR₅,COOR₅ and/or optionally interrupted by one or more O.

X, X′ and X″ for example independently of one another are a single bond,CR_(a)R_(b), O, S, NR_(c) or NCOR_(c); especially O, S, NR_(c) orNCOR_(c), preferably for example O, S, NCOR_(c) or O or S, in particularO.

R₁, R₂, R₃, R₄, R_(a), R_(b) and R_(c) for example independently of oneanother have one of the meanings given for T₁ above, including thecorresponding preferences or for example independently of one anotherare hydrogen, C₁-C₁₂alkyl or phenyl.

In particular preferred are compounds of the formula I, wherein

-   L₁, L₂, L₃, L₄, L₅, L₆, L₇ and L₈ are hydrogen-   L is COT, COR₁ or CN;-   T is C₁-C₂₀alkyl or C₆-C₁₄aryl;-   R₁ is C₁-C₂₀alkyl;-   X is or S;-   Y is halogen or a non-nucleophilic anion, C_(f)F_(2f+1)SO₃ ⁻,    C₁-C₂₀-perfluoroalkylsulphonylmethide, (BF₄)⁻, (SbF₆)⁻, (AsF₆)⁻,    (PF₆)⁻ and (B(C₆F₅)₄)⁻; and-   f is an integer from 1 to 8.

The compounds according to the present invention can for example beprepared by reacting a compound of the formula II with athionylhalogenide, especially thionylchloride in the presence of aFriedel-Crafts catalyst:

L, L₁, L₂, L₃, L₄, L₅, L₆, L₇, L₈ and X are as defined above. Mixturesof different starting compounds of formula II can be used, preferablyonly one kind of starting compound of formula II is used to get atris-symmetrical product.

The reaction suitably is carried out in the presence of a Friedel-Craftscatalyst. Friedel-Crafts catalysts can be Lewis acids and/or strongBronsted acids. Such catalysts are known to the person skilled in theart and published in textbooks of chemistry. The catalysts used forFriedel-Crafts reactions for example are described in George A. Olah,Friedel-Crafts and Related Reactions, Vol. I, 201 and 284-90 (1963).Aluminium trihalides such as AlBr₃ and AlCl₃ are particularly suitable,especially AlCl₃.

Other examples are SnCl₄, ZnCl₂, FeCl₃, HPF₆; rare earth metaltrifluormethanesulfonates (published in Bulletin of the Chemical Societyof Japan, 2000, 73(10), 2325); copper trifluormethanesulfonates (knownfrom Tetrahedron, 2001, 57, 241); uranyl salts (disclosed in Journal ofMolecular Catalysis A: Chemical, 2000, 164(1-2), 195). The use of HF isdescribed in Journal of Organic Chemistry, 1991, 56(20), 5955, while inJournal of Organic Chemistry, 1996, 61(26), 9546 alumina/trifluoroaceticanhydride is employed under microwave conditions. ZnCl₂ as catalyst isknown from Indian Journal of Heterocyclic Chemistry, 2002, 11, 229.

Zeolite catalysts in Friedel Crafts reactions are for example disclosedJ. Molecular Catalysis: Chemical 1998, 134, 121, Applied Catalysis A:General, 2000, 201, 159, while the use of clays or exchanged clays isknown from U.S. Pat. No. 4,304,941.

The application of heteropoly acids or heteropoly acid-containing solidsupports is for example described in Journal of Molecular Catalysis A:Chemical 2004, 209(1-2), 189. Mixtures of Friedel-Crafts catalysts canbe used and mixtures of Friedel-Crafts catalysts with salts like MY ormore specifically MPF₆ or more interestingly with NaPF₆ or KPF₆ can beused.

Suitably the mol ratio of the compound of formula II to theFriedel-Crafts catalyst in the above reaction is for example from 100:1to 1:5; 100:1 to 1:1; 10:1 to 1:1; oris 10:1, 5:1, 3:1, 2:1, 1:1, 1:2,1:3, 1:5, preferably from 10:1 to 1:1.

Sulphination reactions are for example disclosed by S. Smiles and R. LeRossignol in JCS 89 (1906), 696-708 and JCS 93 (1908), 745-762.

The preparation process conveniently is carried out in a solvent.However it is also possible, for example, to use the aromatichydrocarbon of formula II itself, when liquid, as solvent, in which caseit is used in excess. It will be readily understood that the process canalso be carried out in inert solvents. Suitable solvents are, forexample, the solvents described in George A. Olah, Friedel-Crafts andRelated Reactions, Vol. I, 298-302 (1963). The choice of the respectivesolvent depends on the solubility of the educts and catalysts. Typicalexamples of solvents which may be used in the process are halogenatedhydrocarbons such as chlorobenzene, dichlorobenzene, carbontetrachloride, dichloromethane, tetrachloroethylene, bromobenzene,aromatic hydrocarbon derivatives such as nitrobenzene, dinitrobenzene,benzene and toluene, saturated aliphatic hydrocarbons such as pentane,hexane, heptane and the mixtures of isomers thereof, petroleum ether orcyclohexane, or further solvents, typically carbon disulfide,nitroalkanes such as nitromethane, diethyl ether, dimethyl sulfoxide ortetramethylene sulfone.

Dichloromethane, chlorobenzene and dichlorobenzene are preferredsolvents.

The process is generally carried out by mixing the educt compound offormula II with the thionylchloride and reacting said educts in asuitable vessel, which is optionally provided with a heating means. Thereaction optionally is carried out under inert conditions, i.e. thevessel should be equipped with appropriate means to create saidatmosphere by for example working in an atmosphere of nitrogen. Otherinert gases, as for example Ar or He, could also be employed. The personskilled in the art is familiar with these facts.

The reaction of the compound of the formula II with the thionylchloridecan be carried out in different manner. Representative, but notexclusive examples are given below.

-   a) the compound of formula II is placed, together with the catalyst    and the thionylchloride, in the reaction vessel and is immediately    heated to the final reaction temperature, or-   b) the compound of formula II, together with the catalyst and the    thionylchloride, is placed in the reaction vessel and heated slowly    during the reaction to the final temperature, or-   c) the thionylchloride is added during the reaction, to the compound    of formula II and the catalyst which have been previously heated to    the reaction temperature,-   d) the catalyst is suspended in a minimum amount of either one or    both of the starting materials and then the reactants are added    subsequently in any order or are added together.

The reaction vessel also may for example consist of a column that isfilled with the catalyst and the thionylchloride and the compound offormula II are pumped (e.g. continuouesly) over the catalyst through thecolumn.

A further possibility is to bring the reactants together via a reactivedistillation, which is a process in which a catalytic chemical reactionand distillation occur simultaneously in a single apparatus.

The mol ratio of the compound of formula II to the thionylhalogenide inthe above reaction is for example from 10:1 to 1:1; 10:1 to 1:2; or is10:1, 5:1, 4:1, 3.5:1, 3:2, 3:1, 1:1 or 1:2, preferably 3:1.

The reaction temperatures in principle depent on the boiling point ofthe educts and solvents that are employed in the reaction. Saidtemperature is conveniently in the range from −20° C. to about 200° C.,for example from 0° C. to 140° C. or from 0° C. to 100° C., inparticular from 0° C. to 80° C., preferably from 20° C. to 80° C., mostpreferably from 20 to 60° C.

To prepare compounds of the formula I, wherein Y is other than e.g. Cl,the chloride compound is reacted to the compound with the wanted anionby a conventional ion exchange reaction, known to the person skilled inthe art. The anion Y may be already present during the Friedel-Craftsreaction.

To achieve asymmetrical compounds, i.e. compounds, wherein the meaningsof for example L and L′ are not the same a mixture of the correspondingeducts is employed. In particular, a mixture of compounds of the formulaII with II′, or a mixture of compounds of the formula II with compoundsof the formula II′ and II″:

L, L′, L″, L₁, L′₁, L″₁, L₂, L′₂, L″₂, L₃, L′₃, L″₃, L₄, L′₄, L″₄, L₅,L′₅, L″₅, L₆, L″₆, L″₆, L₇, L′₇, L″₇, L₈, L′₈, L″₈, X, X′ and X″ are asdefined above, is employed.

It is of course also possible to synthesize the compounds of formula Ivia a stepwise synthesis through a diaryl-sulfoxide intermediate(synthesis of diarylsulphoxides from arenes and thionylchloride: Oae andZalut, J. Am. Chem. Soc. 82, 5359 (1960), synthesis of diarylsulphoxidesfrom diarylsulfides via oxidation: Drabowicz and Mikolajczyk, Org. Prep.Proced. Int. 14, 45-89 (1982)), which is then further reacted under thefollowing conditions with a third compound of formula (II′) to get acompound of formula (I). Again, the anion can then be exchangedoptionally to an anion Y:

In such a stepwise reaction, three different compounds of formula (II)can be used, or two identical compounds or all identical compounds,

The introduction of the third compound of formula (II) (II′) or (II″) inthe reaction scheme depicted above can be done in a strongly acidicmedium, followed my metathesis with a salt of the desired anion. Severalstrong acids are available as solvents, for example, sulfuric acid,polyphosphoric acid, methanesulfonic acid, or gaseous hydrogen chloride(U.S. Pat. No. 3,488,378). Mixtures of methanesulfonic acid andphosphorus pentoxide (J. Org. Chem. 1990, 55, 4222), or acetic anhydrideand sulphuric acid, or methanesulfonic anhydride are also known. Typicalconditions for these methods are temperatures between −50 and +100° C.Higher temperatures are usually not useful, because of secondaryreactions, such as, for example, sulfonation of one aromatic ring. Lewisacids, such as aluminum chloride in terachloroethylene (WO 03/008404)can also be used. Usually, the sulfonium salt obtained by these methodshas as counteranion the anion derived from one of the acids, forinstance, a hydrogenosulfate, methanesulfonate, ortrifluoromethanesulfonate.

Conditions without metathesis, such as arylation in acetic acid/aceticanhydride/sulfuric acid in the presence of potassium hexafluorophosphateor aqueous 75% HPF₆ are described for example in US 2004/0030158-A.

The starting compounds of formula (II) are for example synthesized e.g.by Friedel-Crafts (FC) reactions:

or for example by substitution reactions, where Hal is a leaving group,e.g. F, Cl, Br, I or triflate, preferably Cl or Br:

Other synthesis routes may be used in analogy to the manufacturingprocesses of [6317-73-3], [6317-78-8], [10169-55-8], [5031-78-7]described in the literature.

The compounds of the formula I are used as photolatent acids, i.ecompounds that upon irradiation release an acid.

Accordingly, an object of the invention is a radiation-sensitivecomposition comprising

-   (a1) a cationically or acid-catalytically polymerisable or    crosslinkable compound or-   (a2) a compound that increases its solubility in a developer under    the action of acid; and-   (b) at least one compound of the formula I as described above.

The compositions according to the invention comprise as component (a1),for example, resins and compounds that can be cationically polymerisedby alkyl- or aryl-containing cations or by protons. Examples thereofinclude cyclic ethers, especially epoxides and oxetanes, and also vinylethers and hydroxy-containing compounds. Lactone compounds and cyclicthioethers as well as vinyl thioethers can also be used. Furtherexamples include aminoplastics or phenolic resole resins. These areespecially melamine, urea, epoxy, phenolic, acrylic, polyester and alkydresins, but especially mixtures of acrylic, polyester or alkyd resinswith a melamine resin. These include also modified surface-coatingresins, such as, for example, acrylic-modified polyester and alkydresins. Examples of individual types of resins that are included underthe terms acrylic, polyester and alkyd resins are described, forexample, in Wagner, Sarx/Lackkunstharze (Munich, 1971), pages 86 to 123and 229 to 238, or in U11-mann/Encyclopädie der techn. Chemie, 4^(th)edition, volume 15 (1978), pages 613 to 628, or Ullmann's Encyclopediaof Industrial Chemistry, Verlag Chemie, 1991, Vol. 18, 360 ff., Vol.A19, 371 ff. The surface-coating preferably comprises an amino resin.Examples thereof include etherified and non-etherified melamine, urea,guanidine and biuret resins. Of special importance is acid catalysis forthe curing of surface-coatings comprising etherified amino resins, suchas, for example, methylated or butylated melamine resins(N-methoxymethyl- or N-butoxymethyl-melamine) or methylated/butylatedglycolurils.

It is possible, for example, to use all customary epoxides, such asaromatic, aliphatic or cycloaliphatic epoxy resins. These are compoundshaving at least one, preferably at least two, epoxy group(s) in themolecule. Examples thereof are the glycidyl ethers and β-methyl glycidylethers of aliphatic or cycloaliphatic diols or polyols, e.g. those ofethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,4-diol,diethylene glycol, polyethylene glycol, polypropylene glycol, glycerol,trimethylolpropane or 1,4-dimethylolcyclohexane or of2,2-bis(4-hydroxycyclohexyl)propane and N,N-bis(2-hydroxyethyl)aniline;the glycidyl ethers of di- and poly-phenols, for example of resorcinol,of 4,4′-dihydroxyphenyl-2,2-propane, of novolaks or of1,1,2,2-tetrakis(4-hydroxyphenyl)ethane. Examples thereof include phenylglycidyl ether, p-tert-butyl glycidyl ether, o-icresyl glycidyl ether,polytetrahydrofuran glycidyl ether, n-butyl glycidyl ether,2-ethylhexylglycidylether, C_(12/15)alkyl glycidyl ether andcyclohexanedimethanol diglycidyl ether. Further examples includeN-glycidyl compounds, for example the glycidyl compounds ofethyleneurea, 1,3-propyleneurea or 5-dimethyl-hydantoin or of4,4′-methylene-5,5′-tetramethydihydantoin, or compounds such astriglycidyl isocyanurate.

Further examples of glycidyl ether components (a1) that are used in theformulations according to the invention are, for example, glycidylethers of polyhydric phenols obtained by the reaction of polyhydricphenols with an excess of chlorohydrin, such as, for example,epichlorohydrin (e.g. glycidyl ethers of2,2-bis(2,3-epoxypropoxyphenol)propane. Further examples of glycidylether epoxides that can be used in connection with the present inventionare described, for example, in U.S. Pat. No. 3,018,262 and in “Handbookof Epoxy Resins” by Lee and Neville, McGraw-Hill Book Co., N.Y. (1967).

There is also a large number of commercially available glycidyl etherepoxides that are suitable as component (a1), such as, for example,glycidyl methacrylate, diglycidyl ethers of bisphenol A, for examplethose obtainable under the trade names EPON 828, EPON 825, EPON 1004 andEPON 1010 (Shell); DER-331, DER-332 and DER-334 (Dow Chemical);1,4-butanediol diglycidyl ethers of phenolformaldehyde novolak, e.g.DEN-431, DEN-438 (Dow Chemical); and resorcinol diglycidyl ethers; alkylglycidyl ethers, such as, for example, C₈-C₁₀glycidyl ethers, e.g.HELOXY Modifier 7, C₁₂-C₁₄glycidyl ethers, e.g. HELOXY Modifier 8, butylglycidyl ethers, e.g. HELOXY Modifier 61, cresyl glycidyl ethers, e.g.HELOXY Modifier 62, p-tert-butylphenyl glycidyl ethers, e.g. HELOXYModifier 65, polyfunctional glycidyl ethers, such as diglycidyl ethersof 1,4-butanediol, e.g. HELOXY Modifier 67, diglycidyl ethers ofneopentyl glycol, e.g. HELOXY Modifier 68, diglycidyl ethers ofcyclohexanedimethanol, e.g. HELOXY Modifier 107, trimethylolethanetriglycidyl ethers, e.g. HELOXY Modifier 44, trimethylolpropanetriglycidyl ethers, e.g. HELOXY Modifier 48, polyglycidyl ethers ofaliphatic polyols, e.g. HELOXY Modifier 84 (all HELOXY glycidyl ethersare obtainable from Shell).

Also suitable are glycidyl ethers that comprise copolymers of acrylicesters, such as, for example, styrene-glycidyl methacrylate or methylmethacrylate-glycidyl acrylate. Examples thereof include 1:1styrene/glycidyl methacrylate, 1:1 methyl methacrylate/glycidylacrylate, 62.5:24:13.5 methyl methacrylate/ethyl acrylate/glycidylmethacrylate.

The polymers of the glycidyl ether compounds can, for example, alsocomprise other functionalities provided that these do not impair thecationic curing.

Other glycidyl ether compounds suitable as component (a1) that arecommercially available are polyfunctional liquid and solid novolakglycidyl ether resins, e.g. PY 307, EPN 1179, EPN 1180, EPN 1182 and ECN9699.

It will be understood that mixtures of different glycidyl ethercompounds may also be used as component (a1).

The glycidyl ethers (a1) are, for example, compounds of formula XX

-   x is a number from 1 to 6; and-   R₅₀ is a mono- to hexavalent alkyl or aryl radical.

Preference is given, for example, to glycidyl ether compounds of formulaXX, wherein

-   x is the number 1, 2 or 3; and-   R₅₀ when x=1, is unsubstituted or C₁-C₁₂alkyl-substituted phenyl,    naphthyl, anthracyl, biphenylyl, C₁-C₂₀alkyl, or C₂-C₂₀alkyl    interrupted by one or more oxygen atoms, or-   R₅₀ when x=2, is 1,3-phenylene, 1,4-phenylene, C₆-C₁₀cycloalkylene,    unsubstituted or halo-substituted C₁-C₄₀alkylene, C₂-C₄₀alkylene    interrupted by one or more oxygen atoms, or a group

-   R₅₀ when x=3, is a radical

-   z is a number from 1 to 10; and-   R₆₀ is C₁-C₂₀alkylene, oxygen or

The glycidyl ethers (a1) are, for example, compounds of formula XXa

-   R₇₀ is unsubstituted or C₁-C₁₂alkyl-substituted phenyl; naphthyl;    anthracyl; biphenylyl;-   C₁-C₂₀alkyl, C₂-C₂₀alkyl interrupted by one or more oxygen atoms; or    a group of formula

-   R₅₀ is phenylene, C₁-C₂₀alkylene, C₂-C₂₀alkylene interrupted by one    or more oxygen atoms, or a group

-   R₆₀ is C₁-C₂₀alkylene or oxygen.

Preference is given to the glycidyl ether compounds of formula XXb

-   R₅₀ is phenylene, C₁-C₂₀alkylene, C₂-C₂₀alkylene interrupted by one    or more oxygen atoms, or a group

-   R₆₀ is C₁-C₂₀alkylene or oxygen.

Further examples for component (a1) are polyglycidyl ethers andpoly(β-methylglycidyl)ethers obtainable by the reaction of a compoundcontaining at least two free alcoholic and/or phenolic hydroxy groupsper molecule with the appropriate epichlorohydrin under alkalineconditions, or alternatively in the presence of an acid catalyst withsubsequent alkali treatment. Mixtures of different polyols may also beused.

Such ethers can be prepared with poly(epichlorohydrin) from acyclicalcohols, such as ethylene glycol, diethylene glycol and higherpoly(oxyethylene)glycols, propane-1,2-diol andpoly(oxypropylene)glycols, propane-1,3-diol, butane-1,4-diol,poly(oxytetramethylene)glycols, pentane-1,5-diol, hexane-1,6-diol,hexane-2,4,6-triol, glycerol, 1,1,1-trimethylol-propane, pentaerythritoland sorbitol, from cycloaliphatic alcohols, such as resorcitol,quinitol, bis(4-hydroxycyclohexyl)methane,2,2-bis(4-hydroxycyclohexyl)propane and1,1-bis-(hydroxyymethyl)cyclohex-3-ene, and from alcohols havingaromatic nuclei, such as N,N-bis(2-hydroxyethyl)aniline andp,p′-bis(2-hydroxyethylamino)diphenylmethane. They can also be preparedfrom mononuclear phenols, such as resorcinol and hydroquinone, andpolynuclear phenols, such as bis(4-hydroxyphenyl)methane,4,4-dihydroxydiphenyl, bis(4-hydroxyphenyl)sulphone,1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,2,2-bis(4-hydroxyphenyl)-propane (bisphenol A) and2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane.

Further hydroxy compounds suitable for the preparation of polyglycidylethers and poly(β-methylglycidyl)ethers are the novolaks obtainable bythe condensation of aldehydes, such as formaldehyde, acetaldehyde,chloral and furfural, with phenols, such as, for example, phenol,o-cresol, m-cresol, p-cresol, 3,5-dimethylphenol, 4-chlorophenol and4-tert-butylphenol.

Poly(N-glycidyl) compounds can be obtained, for example, bydehydrochlorination of the reaction products of epichlorohydrin withamines containing at least two aminohydrogen atoms, such as aniline,n-butylamine, bis(4-aminophenyl)methane, bis(4-aminophenyl)-propane,bis(4-methylaminophenyl)methane and bis(4-aminophenyl)ether, sulphoneand sulphoxide. Further suitable poly(N-glycidyl) compounds includetriglycidyl isocyanurate, and N,N′-diglycidyl derivatives of cyclicalkyleneureas, such as ethyleneurea and 1,3-propyleneurea, andhydantoins, such as, for example, 5,5-dimethylhydantoin.

Poly(S-glycidyl) compounds are also suitable. Examples thereof includethe di-S-glycidyl derivatives of dithiols, such as ethane-1,2-dithioland bis(4-mercaptomethylphenyl)ether.

There also come into consideration as component (a1) epoxy resins inwhich the glycidyl groups or β-methyl glycidyl groups are bonded tohetero atoms of different types, for example the N,N,O-triglycidylderivative of 4-aminophenol, the glycidyl ether/glycidyl ester ofsalicylic acid or p-hydroxybenzoic acid,N-glycidyl-N′-(2-glycidyloxypropyl)-5,5-dimethylhydantoin and2-glycidyloxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

Preference is given to diglycidyl ethers of bisphenols. Examples thereofinclude diglycidyl ethers of bisphenol A, e.g. ARALDIT GY 250,diglycidyl ethers of bisphenol F and diglycidyl ethers of bisphenol S.Special preference is given to diglycidyl ethers of bisphenol A.

Further glycidyl compounds of technical importance are the glycidylesters of carboxylic acids, especially di- and poly-carboxylic acids.Examples thereof are the glycidyl esters of succinic acid, adipic acid,azelaic acid, sebacic acid, phthalic acid, terephthalic acid, tetra- andhexa-hydrophthalic acid, isophthalic acid or trimellitic acid, or ofdimerised fatty acids.

Examples of polyepoxides that are not glycidyl compounds are theepoxides of vinylcyclohexane and dicyclopentadiene,3-(3′,4′-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro-[5.5]undecane, the3′,4′-epoxycyclohexylmethyl esters of 3,4-epoxycyclohexanecarboxylicacid, (3,4-epoxycyclohexyl-methyl 3,4-epoxycyclohexanecarboxylate),butadiene diepoxide or isoprene diepoxide, epoxidised linoleic acidderivatives or epoxidised polybutadiene.

Further suitable epoxy compounds are, for example, limonene monoxide,epoxidised soybean oil, bisphenol-A and bisphenol-F epoxy resins, suchas, for example, Araldit® GY 250 (A), ARALDIT® GY 282 (F), ARALDIT® GY285 (F)), and photocurable siloxanes that contain epoxy groups.

Further suitable cationically polymerisable or crosslinkable components(a1) can be found, for example, also in U.S. Pat. No. 3,117,099, U.S.Pat. No. 4,299,938 and U.S. Pat. No. 4,339,567.

From the group of aliphatic epoxides there are suitable especially themonofunctional symbol α-olefin epoxides having an unbranched chainconsisting of 10, 12, 14 or 16 carbon atoms.

Because nowadays a large number of different epoxy compounds arecommercially available, the properties of the binder can vary widely.One possible variation, for example depending upon the intended use ofthe composition, is the use of mixtures of different epoxy compounds andthe addition of flexibilisers and reactive diluents.

The epoxy resins can be diluted with a solvent to facilitateapplication, for example when application is effected by spraying, butthe epoxy compound is preferably used in the solventless state. Resinsthat are viscous to solid at room temperature can be applied hot.

Also suitable as component (a1) are all customary vinyl ethers, such asaromatic, aliphatic or cycloaliphatic vinyl ethers and alsosilicon-containing vinyl ethers. These are compounds having at leastone, preferably at least two, vinyl ether groups in the molecule.Examples of vinyl ethers suitable for use in the compositions accordingto the invention include triethylene glycol divinyl ether,1,4-cyclohexanedimethanol divinyl ether, 4-hydroxybutyl vinyl ether, thepropenyl ether of propylene carbonate, dodecyl vinyl ether, tert-butylvinyl ether, tert-amyl ylnyl ether, cyclohexyl vinyl ether, 2-ethylhexylvinyl ether, ethylene glycol monovinyl ether, butanediol monovinylether, hexanediol monovinyl ether, 1,4-cyclohexanedimethanol monovinylether, diethylene glycol monovinyl ether, ethylene glycol divinyl ether,ethylene glycol butylvinyl ether, butane-1,4-diol divinyl ether,hexanediol divinyl ether, diethylene glycol divinyl ether, triethyleneglycol divinyl ether, triethylene glycol methylvinyl ether,tetra-ethylene glycol divinyl ether, pluriol-E-200 divinyl ether,polytetrahydrofuran divinyl ether-290, trimethylolpropane trivinylether, dipropylene glycol divinyl ether, octadecyl vinyl ether,(4-cyclohexylmethyleneoxyethene)-glutaric acid methyl ester and(4-butoxyethene)-iso-phthalic acid ester.

Examples of hydroxy-containing compounds include polyester polyols, suchas, for example, polycaprolactones or polyester adipate polyols, glycolsand polyether polyols, castor oil, hydroxy-functional vinyl and acrylicresins, cellulose esters, such as cellulose acetate butyrate, andphenoxy resins.

Further cationically curable formulations can be found, for example, inEP 119425.

As component (a1), preference is given to cycloaliphatic epoxides, orepoxides based on bisphenol A.

Accordingly, the invention relates also to a radiation-sensitivecomposition wherein component (a1) is at least one compound selectedfrom the group of cycloaliphatic epoxy compounds, glycidyl ethers,oxetane compounds, vinyl ethers, acid-crosslinkable melamine resins,acid-crosslinkable hydroxymethylene compounds and acid-crosslinkablealkoxy-methylene compounds.

If desired, the composition according to the invention can also containfree-radically polymerisable components, such as ethylenicallyunsaturated monomers, oligomers or polymers. These radicallypolymerizable components may be added to either component (a1) orcomponent (a2). Said radically curable components may, however, also bepart of (a1) or (a2), see description of (A1), (A2) and (A3), componentscomprising both, radically crosslinking and cationically crosslinkinggroups, further below. Suitable materials contain at least oneethylenically unsaturated double bond and are capable of undergoingaddition polymerisation.

Examples of suitable monomers that contain an ethylenic double bondinclude alkyl and hydroxyalkyl acrylates and methacrylates, such asmethyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl and2-hydroxyethyl (meth)acrylate, stearyl acrylate and isobornyl acrylates.Further suitable examples include acrylonitrile, acrylamide,methacrylamide, N-substituted (meth)acrylamides, vinyl esters, such asvinyl acetate, vinyl ethers, such as isobutylvinyl ether, styrene,alkyl- and halo-substituted styrene, N-vinylpyrrolidone, vinyl chlorideand vinylidene chloride.

Examples of suitable monomers that contain at least two double bondsinclude glycerol diacrylates, glycerol triacrylates, ethylene glycoldiacrylates, diethylene glycol diacrylates, diethylene glycoldimethacrylate, triethylene glycol dimethacrylates, 1,3-propanedioldiacrylate, 1,3-propanediol dimethacrylate, neopentyl glycoldiacrylates, hexamethylene glycol diacrylate, bisphenol-A diacrylates,4,4′-bis(2-acryloyloxyethoxy)diphenylpropane, pentaerythritoltriacrylate or tetraacrylate, pentaerythritol tetramethacrylate,trimethylolpropane triacrylate, 1,2,4-butanetriol trimethacrylate,1,4-cyclohexanediol diacrylate, sorbitol hexaacrylate,bis[1-(2-acryloxy)]-p-ethoxyphenyldimethylmethane,bis[1-(3-acryloxy-2-hydroxy)]-p-propoxyphenyldimethylmethane andtrishydroxyethyl isocyanurate trimethacrylate; the bisacrylates andbis-methacrylates of poly(ethylene glycol) having a molecular weight offrom 200 to 500, diallyl phthalate, divinyl succinate, divinyl adipateand divinyl phthalate, vinyl acrylate, divinyl benzene, triallylphosphate, triallyl isocyanurates and tris(2-acryloyl-ethyl)isocyanurate.

Examples of higher-molecular-weight (oligomeric) poly-unsaturatedcompounds include acrylated epoxy resins, acrylated or vinyl ether- orepoxy-group-containing polyesters, polyurethanes and polyethers. Furtherexamples of unsaturated oligomers are unsaturated polyester resins,which are usually prepared from maleic acid, phthalic acid and one ormore diols and have molecular weights of approximately from 500 to 3000.Vinyl ether monomers and oligomers, and maleate-terminated oligomershaving polyester, poly-urethane, polyether, polyvinyl ether and epoxymain chains can also be used. Also copolymers of vinyl ethers andmonomers which are functionalised with maleic acid, as described in WO90/01512, are also very suitable. Also suitable, however, are copolymersof monomers functionalised with vinyl ether and maleic acid. Suchunsaturated oligomers can also be referred to as pre-polymers.Functionalised acrylates are also suitable. Examples of suitablemonomers that are normally used to form the base polymer (the backbone)of the functionalised acrylate or methacrylate polymer are acrylate,methacrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate,n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutylmethacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. Inaddition, suitable amounts of functional monomers are copolymerisedduring the polymerisation in order to obtain the functional polymers.Acid-functionalised acrylate or methacrylate polymers are obtained usingacid-functional monomers, such as acrylic acid and methacrylic acid.Hydroxy-functional acrylate or methacrylate polymers are obtained fromhydroxy-functional monomers, such as 2-hydroxyethyl methacrylate,2-hydroxypropyl methacrylate and 3,4-dihydroxybutyl methacrylate.Epoxy-functionalised acrylate or methacrylate polymers are obtainedusing epoxy-functional monomers, such as glycidyl methacrylate,2,3-epoxybutyl methacrylate, 3,4-epoxybutyl methacrylate,2,3-epoxycyclohexyl methacrylate, 10,11-epoxyundecyl meth-acrylate, etc.It is also possible to obtain isocyanate-functional polymers fromisocyanate-functionalised monomers, such asmeta-isopropenyl-α,α-dimethylbenzyl isocyanate.

Especially suitable are, for example, esters of ethylenicallyunsaturated mono- or polyfunctional carboxylic acids and polyols orpolyepoxides, and polymers having ethylenically unsaturated groups inthe chain or in side groups, such as unsaturated polyesters, polyamidesand polyurethanes and copolymers thereof, alkyd resins, polybutadieneand butadiene copolymers, polyisoprene and isoprene copolymers, polymersand copolymers having (meth)acrylic groups in side chains, and mixturesof one or more such polymers.

Examples of suitable mono- or poly-functional unsaturated carboxylicacids are acrylic acid, methacrylic acid, crotonic acid, itaconic acid,cinnamic acid, maleic acid and fumaric acid and unsaturated fatty acids,such as linolenic acid or oleic acid. Preference is given to acrylicacid and methacrylic acid.

Mixtures of saturated di- or poly-carboxylic acids with unsaturatedcarboxylic acids may, however, also be used. Examples of suitablesaturated di- or poly-carboxylic acids include, for example,tetrachlorophthalic acid, tetrabromophthalic acid, phthalic acidanhydride, adipic acid, tetrahydrophthalic acid, isophthalic acid,terephthalic acid, trimellitic acid, heptanedicarboxylic acid, sebacicacid, dodecanedicarboxylic acid, hexahydrophthalic acid, etc.

Suitable polyols are aromatic and especially aliphatic andcycloaliphatic polyols. Examples of aromatic polyols are hydroquinone,4,4′-dihydroxydiphenyl, 2,2-di(4-hydroxyphenyl)-propane, and novolaksand resoles. Examples of polyepoxides are those based on the polyolsmentioned, especially the aromatic polyols and epichlorohydrin. Alsosuitable as polyols are polymers and copolymers containing hydroxylgroups in the polymer chain or in side groups, such as polyvinyl alcoholand copolymers thereof or polymethacrylic acid hydroxyalkyl esters orcopolymers thereof. Further suitable polyols are oligoesters havinghydroxyl terminal groups.

Examples of aliphatic and cycloaliphatic polyols are alkylenediolshaving preferably from 2 to 12 carbon atoms, such as ethylene glycol,1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol,hexanediol, octanediol, dodecanediol, diethylene glycol, triethyleneglycol, polyethylene glycols having molecular weights of preferably from200 to 1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-dihydroxymethylcyclohexane, glycerol, tris(β-hydroxyethyl)amine,trimethylolethane, trimethylolpropane, pentaerythritol,dipentaerythritol and sorbitol.

The polyols may be partially or fully esterified by one or by differentunsaturated carboxylic acid(s), it being possible for the free hydroxylgroups in partial esters to have been modified, for example etherified,or esterified by other carboxylic acids.

Examples of esters are:

-   trimethylolpropane triacrylate, trimethylolethane triacrylate,    trimethylolpropane trimethacrylate, trimethylolethane    trimethacrylate, tetramethylene glycol dimethacrylate, triethylene    glycol dimethacrylate, tetraethylene glycol diacrylate,    pentaerythritol diacrylate, penta-erythritol triacrylate,    pentaerythritol tetraacrylate, dipentaerythritol diacrylate,    dipenta-erythritol triacrylate, dipentaerythritol tetraacrylate,    dipentaerythritol pentaacrylate, dipenta-erythritol hexaacrylate,    tripentaerythritol octaacrylate, pentaerythritol dimethacrylate,    penta-erythritol trimethacrylate, dipentaerythritol dimethacrylate,    dipentaerythritol tetrameth-acrylate, tripentaerythritol    octamethacrylate, pentaerythritol diitaconate, dipentaerythritol    trisitaconate, dipentaerythritol pentaitaconate, dipentaerythritol    hexaitaconate, ethylene glycol diacrylate, 1,3-butanediol    diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol    diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,    pentaerythritol-modified triacrylate, sorbitol tetramethacrylate,    sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates    and methacrylates, glycerol di-and tri-acrylate, 1,4-cyclohexane    diacrylate, bisacrylates and bismethacrylates of polyethylene glycol    having a molecular weight of from 200 to 1500, and mixtures thereof.

Suitable unsaturated, free-radically polymerisable compounds are alsothe amides of the same or different unsaturated carboxylic acids andaromatic, cycloaliphatic and aliphatic polyamines having preferably from2 to 6, especially from 2 to 4, amino groups. Examples of suchpolyamines are ethylenediamine, 1,2- or 1,3-propylenediamine, 1,2-, 1,3-or 1,4-butylenediamine, 1,5-pentylenediamine, 1,6-hexylenediamine,octylenediamine, dodecylenediamine, 1,4-diaminocyclohexane,isophoronediamine, phenylenediamine, bisphenylenediamine,di-β-aminoethyl ether, diethylenetriamine, triethylenetetraamine anddi(β-aminoethoxy)- or di(β-aminopropoxy)-ethane. Further suitablepolyamines are polymers and copolymers which may have additional aminogroups in the side chain and oligoamides having amino terminal groups.Examples of such unsaturated amides are: methylene bisacrylamide,1,6-hexamethylene bisacrylamide, bis(methacrylamidopropoxy)ethane,β-methacrylamidoethyl methacrylate andN-[(β-hydroxyethoxy)ethyl]-acrylamide.

Suitable unsaturated polyesters and polyamides are derived, for example,from maleic acid and diols or diamines. The maleic acid may have beenpartially replaced by other dicarboxylic acids. They can be usedtogether with ethylenically unsaturated comonomers, for example styrene.The polyesters and polyamides can also be derived from dicarboxylicacids and ethylenically unsaturated diols or diamines, especially fromthose having longer chains of, for example, from 6 to 20 carbon atoms.Examples of polyurethanes are those composed of saturated or unsaturateddiisocyanates and saturated or unsaturated diols.

Polybutadiene and polyisoprene and copolymers thereof are known.Suitable comonomers include, for example, olefins, such as ethylene,propene, butene, hexene, (meth)acrylates, acrylonitrile, styrene andvinyl chloride. Polymers having (meth)acrylate groups in the side chainare also known. They may be, for example, reaction products ofnovolak-based epoxy resins with (meth)acrylic acid; homo- or co-polymersof vinyl alcohol or hydroxyalkyl derivatives thereof that have beenesterified with (meth)acrylic acid; or homo- and co-polymers of(meth)acrylates that have been esterified with hydroxyalkyl(meth)acrylates.

It is also possible to use compounds that can be crosslinked equallyboth free-radically and cationically. Such compounds contain, forexample, both a vinyl group and a cycloaliphatic epoxy group. Examplesthereof are described in JP 2-289611-A and U.S. Pat. No. 6,048,953.

Mixtures of two or more such free-radically polymerisable materials canalso be used.

Binders may also be added to the compositions according to theinvention, this being especially advantageous when thephotopolymerisable compounds are liquid or viscous substances. Theamount of binder may be, for example, from 5 to 95% by weight,preferably from 10 to 90% by weight and especially from 40 to 90% byweight, based on total solids. The binder will be selected according tothe field of use and the properties required therefor, such asdevelopability in aqueous and organic solvent systems, adhesion tosubstrates and sensitivity to oxygen.

Suitable binders are, for example, polymers having a molecular weight ofapproximately from 2000 to 2 000 000, preferably from 5000 to 1 000 000.Examples thereof are: homo- and copolymers of acrylates andmethacrylates, for example copolymers of methyl methacrylate/ethylacrylate/methacrylic acid, poly(methacrylic acid alkyl esters),poly(acrylic acid alkyl esters); phenolic resins, cellulose derivatives,such as cellulose esters and ethers, for example cellulose acetate,cellulose acetate butyrate, methyl cellulose, ethyl cellulose; polyvinylbutyral, polyvinylformal, polyolefins, cyclised rubber, polyethers, suchas poly-ethylene oxide, polypropylene oxide, polytetrahydrofuran;polystyrene, polycarbonate, poly-urethane, chlorinated polyolefins,polyvinyl chloride, copolymers of vinyl chloride/vinylidene chloride,copolymers of vinylidene chloride with acrylonitrile, methylmethacrylate and vinyl acetate, polyvinyl acetate, copoly(ethylene/vinylacetate), polymers such as polycaprolactam andpoly(hexamethyleneadipamide), polyesters such as poly(ethylene glycolterephthalate) and poly(hexamethylene glycol succinate); and polyamides.

The resins mentioned below under (C1) may also be used as free-radicallycurable component. Of particular interest are, for example, unsaturatedacrylates having reactive functional groups. The reactive functionalgroup may be selected, for example, from a hydroxyl, thiol, isocyanate,epoxy, anhydride, carboxyl, amino or blocked amino group. Examples ofOH-group-containing unsaturated acrylates are hydroxyethyl andhydroxybutyl acrylates and also glycidyl acrylates.

The unsaturated compounds may also be used in admixture withnon-photopolymerisable film-forming components. These may be, forexample, polymers that can be dried physically or solutions thereof inorganic solvents, such as nitrocellulose or cellulose acetobutyrate.They may alternatively be chemically or thermally curable resins, suchas polyisocyanates, polyepoxides or melamine resins. Drying oils, suchas linseed oil, linseed-oil-modified alkyd resins, tung oil and soybeanoil, can also be present. The concomitant use of thermally curableresins is important for use in so-called hybrid systems which arephotopolymerised in a first step and crosslinked by thermalaftertreatment in a second step.

Thus, the radiation-curable compositions of the present invention mayalso comprise:

-   (A1) compounds having one or more free-radically polymerisable    double bonds that additionally contain at least one further    functional group that is reactive in addition and/or condensation    reactions (examples are given above),-   (A2) compounds having one or more free-radically polymerisable    double bonds that additionally contain at least one further    functional group that is reactive in addition and/or condensation    reactions, the additional functional group being complementary to or    reactive towards the additional functional group of component (A1),-   (A3) at least one monomeric, oligomeric and/or polymeric compound    having at least one functional group that is reactive in addition    and/or condensation reactions towards the functional groups of    component (A1) or (A2) that are present in addition to the    free-radically polymerisable double bonds.

Component (A2) in each case carries the groups complementary to orreactive towards component (A1). Different types of functional groupsmay also be present in a component. Component (A3) provides a componentthat contains further functional groups that are reactive in additionand/or condensation reactions and that are able to react with thefunctional groups of (A1) or (A2) that are present in addition to thefree-radically polymerisable double bonds. Component (A3) contains nofree-radically polymerisable double bonds.

Examples of such combinations (A1), (A2), (A3) can be found in WO99/55785.

Examples of suitable functional groups are hydroxyl, isocyanate, epoxy,anhydride, carboxyl and blocked amino groups. Examples have beendescribed above.

Constituents of the thermally curable component (C) are, for example,thermally curable lacquer or coating system constituents customary inthe art. Component (C) accordingly may consist of a large number ofconstituents.

Examples of component (C) include oligomers and/or polymers derived fromα,β-unsaturated acids and derivatives thereof, for example polyacrylatesand polymethacrylates, polymethyl methacrylatesimpact-resistant-modified with butyl acrylate, polyacrylamides andpolyacrylonitriles. Further examples of component (C) are urethanes,polyurethanes derived on the one hand from polyethers, polyesters andpolyacrylates having free hydroxyl groups and on the other hand fromaliphatic or aromatic polyisocyanates, and educts thereof. Component (C)accordingly also includes, for example, crosslinkable acrylic resinsderived from substituted acrylic acid esters, for example epoxyacrylates, urethane acrylates and polyester acrylates. Alkyd resins,polyester resins and acrylate resins and modifications thereof that arecrosslinked with melamine resins, urea resins, isocyanates,isocyanurates, polyisocyanates, polyisocyanurates and epoxy resins, mayalso be a constituent of component (C).

Component (C) is, for example, generally a film-forming binder based ona thermoplastic or thermocurable resin, especially on a thermocurableresin. Examples thereof are alkyd, acrylic, polyester, phenolic,melamine, epoxy and polyurethane resins and mixtures thereof. Examplesthereof can be found, for example, in Ullmann's Encyclopedia ofIndustrial Chemistry, 5th Ed., Vol. A18, pp. 368-426, VCH, Weinheim1991.

Component (C) may also be a cold-curable or hot-curable binder, in whichcase the addition of a curing catalyst may be advantageous. Suitablecatalysts that accelerate the full cure of the binder can be found, forexample, in Ullmann's Encyclopedia of Industrial Chemistry, Vol. A18,page 469, VCH Verlagsgesellschaft, Weinheim 1991.

Specific examples of binders suitable as component (C) are:

-   1. surface-coatings based on cold- or hot-crosslinkable alkyd,    acrylate, polyester, epoxy or melamine resins or mixtures of such    resins, optionally with the addition of a curing catalyst;-   2. two-component polyurethane surface-coatings based on    hydroxyl-group-containing acrylate, polyester or polyether resins    and aliphatic or aromatic isocyanates, isocyanurates or    polyisocyanates;-   3. one-component polyurethane surface-coatings based on blocked    isocyanates, isocyanurates or polyisocyanates, which are de-blocked    during heating; it is also possible to add melamine resins as    appropriate;-   4. one-component polyurethane surface-coatings based on aliphatic or    aromatic urethanes or polyurethanes and hydroxyl-group-containing    acrylate, polyester or polyether resins;-   5. one-component polyurethane surface-coatings based on aliphatic or    aromatic urethane acrylates or polyurethane acrylates having free    amine groups in the urethane structure and melamine resins or    polyether resins, optionally with the addition of a curing catalyst;-   6. two-component surface-coatings based on (poly)ketimines and    aliphatic or aromatic isocyanates, isocyanurates or polyisocyanates;-   7. two-component surface-coatings based on (poly)ketimines and an    unsaturated acrylate resin or a polyacetoacetate resin or a    methacrylamidoglycolate methyl ester;-   8. two-component surface-coatings based on carboxyl- or    amino-group-containing polyacrylates and polyepoxides;-   9. two-component surface-coatings based on    anhydride-group-containing acrylate resins and a polyhydroxy or    polyamino component;-   10. two-component surface-coatings based on acrylate-containing    anhydrides and polyepoxides;-   11. two-component surface-coatings based on (poly)oxazolines and    anhydride-group-containing acrylate resins or unsaturated acrylate    resins or aliphatic or aromatic isocyanates, isocyanurates or    polyisocyanates;-   12. two-component surface-coatings based on unsaturated    polyacrylates and polymalonates;-   13. thermoplastic polyacrylate surface-coatings based on    thermoplastic acrylate resins or extrinsically crosslinking acrylate    resins in combination with etherified melamine resins;-   14. surface-coating systems based on urethane (meth)acrylate having    (meth)acryloyl groups and free isocyanate groups and on one or more    compounds that react with iso-cyanates, for example free or    esterified polyols. Such systems have been published, for example,    in EP 928800.

Blocked isocyanates that can also be used as component (C) aredescribed, for example, in Organischer Metallschutz Entwicklung undAnwendung von Beschichtungsstoffen, pages 159-160, Vincentz Verlag,Hanover (1993). These are compounds in which the highly reactive NCOgroup is “blocked” by reaction with specific radicals, for example aprimary alcohol, phenol, acetic acid ethyl ester, ε-caprolactam,phthalimide, imidazole, oxime or amine. The blocked isocyanate is stablein liquid systems and also in the presence of hydroxy groups. Uponheating, the blocking group (protecting group) is removed again and theNCO group is freed.

1-Component (1C) and 2-component (2C) systems may be used as component(C). Examples of such systems are described in Ullmann's Encyclopedia ofIndustrial Chemistry, Vol. A18, Paints and Coatings, pages 404-407, VCHVerlagsgesellschaft mbH, Weinheim (1991). It is possible to optimise thecomposition by specific adaptation, for example by varying thebinder/crosslinking agent ratios. Such measures will be known to theperson skilled in the art and are customary in coating technology.

In the curing process according to the invention, component (C) ispreferably a mixture based on acrylate/melamine (and melaminederivatives), 2-component polyurethane, 1-component polyurethane,2-component epoxy/carboxy or 1-component epoxy/carboxy. Mixtures of suchsystems are also possible, for example the addition of melamine (orderivatives thereof) to 1-component polyurethanes.

Component (C) is preferably a binder based on a polyacrylate withmelamine or on a melamine derivative or a system based on a polyacrylateand/or polyester polyol with an unblocked polyisocyanate orpolyisocyanurate.

Component (C) may also comprise monomeric and/or oligomeric compoundshaving ethylenically unsaturated bonds (prepolymers) that additionallycontain at least one or more OH, NH₂, COOH, epoxy or NCO group(s) (=C1)that are capable of reaction with the binder and/or the crosslinkingagent constituent of component (C). After application and thermalcuring, the ethylenically unsaturated bonds are converted to acrosslinked, high molecular weight form by irradiation with UV light.Examples of such components (C) are described, for example, in theabove-mentioned publication, Ullmann's Encyclopedia of IndustrialChemistry, 5th Ed., Vol. A18, pages 451-453, or by S. Urano, K. Aoki, N.Tsuboniva and R. Mizuguchi in Progress in Organic Coatings, 20 (1992),471-486, or by H. Terashima and O. Isozaki in JOCCA 1992 (6), 222.

(C1) may, for example, also be an OH-group-containing unsaturatedacrylate, for example hydroxyethyl or hydroxybutyl acrylate or aglycidyl acrylate. Component (C1) may be of any desired structure (forexample it may contain units of polyester, polyacrylate, polyether,etc.), provided that it contains an ethylenically unsaturated doublebond and additionally free OH, COOH, NH₂, epoxy or NCO groups.

(C1) may, for example, also be obtained by reacting an epoxy-functionaloligomer with acrylic acid or methacrylic acid. A typical example of anOH-functional oligomer having vinylic double bonds is

obtained by reaction of CH₂═CHCOOH with

Another possible method of obtaining component (C1) is, for example, thereaction of an oligomer that contains only one epoxy group and has afree OH group at another position in the molecule.

The quantity ratio of the free-radically radiation-curable-polymerisablecomponents to the thermally polymerisable component (C) in the UV- andthermally-crosslinkable formulations is not critical. “Dual-cure”systems are known to the person skilled in the art, who will thereforebe familiar with the optimum mixing ratios of the free-radically- andthermally-crosslinkable components according to the intended use. Forexample, the ratio can be in the range from 5:95 to 95:5, from 20:80 to80:20 or from 30:70 to 70:30, for example from 40:60 to 60:40.

Examples of “dual-cure” systems, that is to say systems comprising bothradiation-curable and thermally curable components, can be found interalia in U.S. Pat. No. 5,922,473, columns 6 to 10.

The formulations according to the invention can further comprise ascomponent (a1) non-aqueous coating compositions based on an oxidativelydrying alkyd resin which contains at least one, preferably two or more,functional group(s) capable of undergoing polymerisation orpolycondensation reactions in the presence of an acid. Examples of suchresins are vinyl-ether-functionalised alkyd resins,acetal-functionalised alkyd resins, and/or alkoxysilane-functionalisedalkyd resins, as proposed, e.g., in WO 99/47617. Those modified alkydresins may be used alone or in combination with other alkyd resins. Atleast some of the alkyd resin composition in the non-aqueous coating isoxidatively drying as a result of the incorporation of a large number ofunsaturated, aliphatic compounds, at least some of which arepolyunsaturated.

Formulations containing those modified alkyd resins as component (a1)may optionally contain, in addition to the photoinitiator (b), anoxidative dryer. Suitable oxidative dryers are, for example, metalsiccatives. There may be mentioned as suitable siccatives, for example,the metal salts of (cyclo)aliphatic acids, such as octanoic acid andnaphthenic acid, the metals to be used being, for example, cobalt,manganese, lead, zirconium, calcium, zinc and rare earth metals.Mixtures of siccatives may be used. Preference is given to metal saltsof cobalt, zirconium and calcium, or mixtures thereof. The siccatives(calculated as metal) are usually used in an amount of from 0.001 to 3%by weight.

Under certain conditions it may also be advantageous, when using themodified alkyd resins as component (a1), to use one or more mono- orbis-acylphosphine oxide photoinitiators in addition to the sulphoniumsalt of formula (I). Suitable monoacyl- or bisacyl-phosphine oxidephotoinitiators include, for example, monoacylphosphine oxides such as(2,4,6-trimethylbenzoyl)-diphenylphosphine oxide (DAROCUR®TPO) or(2,4,6-trimethylbenzoylphenyl-ethoxy-phosphine oxide, orbisacylphosphine oxide photoinitiators such asbis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl-phosphine oxide,bis(2,4,6-trimethylbenzoyl)-(2,4-dipentyloxyphenyl)-phosphine oxide andbis(2,4,6-trimethylbenzoyl)phenyl-phosphine oxide (IRGACURE®819). Thosemonoacyl- or bisacylphosphine oxides are advantageously used in anamount of from 0.5 to 5%.

When component (a1) contains modified alkyd resins, in addition to thephotoinitiator (b) it is also possible to use an oxidative dryer andsuitable monoacyl- or bisacyl-phosphine oxide photoinitiators.

The alkyd resins used as component (a1) contain a large number ofunsaturated, aliphatic compounds, at least some of which arepolyunsaturated. The unsaturated aliphatic compounds preferably used forthe preparation of those alkyd resins are unsaturated aliphaticmonocarboxylic acids, especially polyunsaturated aliphaticmonocarboxylic acids.

Examples of mono-unsaturated fatty acids are myristoleic acid, palmiticacid, oleic acid, gadoleic acid, erucic acid and ricinoleic acid.Preferably fatty acids containing conjugated double bonds, such asdehydrogenated castor oil fatty acid and/or tung oil fatty acid, areused. Other suitable monocarboxylic acids include tetrahydrobenzoic acidand hydrogenated or non-hydrogenated abietic acid or the isomersthereof. If desired, the monocarboxylic acid in question may be usedwholly or in part in the form of a triglyceride, e.g. as vegetable oil,in the preparation of the alkyd resin. If desired, mixtures of two ormore such mono-carboxylic acids or triglycerides may be used, optionallyin the presence of one or more saturated, (cyclo)aliphatic or aromaticmonocarboxylic acids, e.g. pivalic acid, 2-ethyl-hexanoic acid, lauricacid, palmitic acid, stearic acid, 4-tert-butyl-benzoic acid,cyclo-pentanecarboxylic acid, naphthenic acid, cyclohexanecarboxylicacid, 2,4-dimethylbenzoic acid, 2-methylbenzoic acid and benzoic acid.

If desired, polycarboxylic acids may also be incorporated into the alkydresin, such as phthalic acid, isophthalic acid, terephthalic acid,5-tert-butylisophthalic acid, trimellitic acid, pyromellitic acid,succinic acid, adipic acid, 2,2,4-trimethyladipic acid, azelaic acid,sebacic acid, dimerised fatty acids, cyclopentane-1,2-dicarboxylic acid,cyclohexane-1,2-dicarboxylic acid, 4-methylcyclohexane-1,2-dicarboxylicacid, tetrahydrophthalic acid, endomethylenecyclohexane-1,2-dicarboxylicacid, butane-1,2,3,4-tetracarboxylic acid,endoisopropylidenecyclohexane-1,2-dicarboxylic acid,cyclohexane-1,2,4,5-tetracarboxylic acid andbutane-1,2,3,4-tetracarboxylic acid. If desired, the carboxylic acid inquestion may be used as an anhydride or in the form of an ester, forexample an ester of an alcohol having from 1 to 4 carbon atoms.

In addition, the alkyd resin can be composed of di- or poly-valenthydroxyl compounds. Examples of suitable divalent hydroxyl compounds areethylene glycol, 1,3-propanediol, 1,6-hexanediol, 1,12-dodecanediol,3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexane-diol,2,2-dimethyl-1,3-propanediol and 2-methyl-2-cyclohexyl-1,3-propanediol.Examples of suitable triols are glycerol, trimethylolethane andtrimethylolpropane. Suitable polyols having more than 3 hydroxyl groupsare pentaerythritol, sorbitol and etherified products of the compoundsin question, such as ditrimethylolpropane and di-, tri- andtetra-pentaerythritol. Preferably, compounds having from 3 to 12 carbonatoms, e.g. glycerol, pentaerythritol and/or dipentaerythritol, areused.

The alkyd resins can be obtained by direct esterification of theconstituents, with the option that some of those components may alreadyhave been converted into ester diols or polyester diols. The unsaturatedfatty acids can also be used in the form of a drying oil, such aslinseed oil, tuna fish oil, dehydrogenated castor oil, coconut oil anddehydrogenated coconut oil. The final alkyd resin is then obtained bytransesterification with the other acids and diols added. Thetransesterification is advantageously carried out at a temperature inthe range of from 115 to 250° C., optionally in the presence of solventssuch as toluene and/or xylene. The reaction is advantageously carriedout in the presence of a catalytic amount of a transesterificationcatalyst. Examples of suitable transesterification catalysts includeacids, such as p-toluenesulphonic acid, basic compounds, such as anamine, or compounds such as calcium oxide, zinc oxide, tetraisopropylorthotitanate, dibutyltin oxide and tri-phenylbenzylphosphoniumchloride.

The vinyl ether, acetal and/or alkoxysilane compounds used as part ofcomponent (a1) preferably contain at least two vinyl ether, acetaland/or alkoxysilane groups and have a molecular weight of 150 or more.Those vinyl ether, acetal and/or alkoxysilane compounds can be obtained,for example, by the reaction of a commercially available vinyl ether,acetal and/or alkoxysilane compound containing a vinyl ether, acetaland/or alkoxysilane group and in addition a maximum of one functionalamino, epoxy, thiol, isocyanate, acrylic, hydride or hydroxyl group,with a compound having at least two groups capable of reacting with anamino, epoxy, thiol, isocyanate, acrylic, hydride or hydroxyl group. Asexamples thereof there may be mentioned compounds having at least twoepoxy, isocyanate, hydroxyl and/or ester groups or compounds having atleast two ethylenically or ethynylenically unsaturated groups. Ascomponent (a1), preference is given to a composition in which the vinylether, acetal and/or alkoxysilane compounds are covalently bonded to thealkyd resin by addition via a reactive group such as an amino, hydroxyl,thiol, hydride, epoxy and/or isocyanate group. For that purpose, thecompounds must have at least one group capable of forming an adduct withthe reactive groups present in the alkyd resin.

To incorporate vinyl ether groups into the alkyd resin, use is made of avinyloxyalkyl compound, the alkyl group of which is substituted by areactive group, such as a hydroxyl, amino, epoxy or isocyanate group,that is capable of forming an adduct with one or more of the reactivegroups present in the alkyd resin.

As component (a1), preference is given to compositions in which theratio of the number of oxidatively drying groups present in the alkydresin to the number of groups that are reactive in the presence of anacid is in the range of from 1/10 to 15/1, especially from 1/3 to 5/1.Instead of a single modified alkyd resin, it is also possible to use aplurality of alkyd resins, with one alkyd resin being highly modifiedand the others being less modified or not modified at all.

Examples of vinyl ether compounds capable of being covalently bonded tothe alkyd resin are ethylene glycol monovinyl ether, butanediolmonovinyl ether, hexanediol monovinyl ether, triethylene glycolmonovinyl ether, cyclohexanedimethanol monovinyl ether,2-ethylhexanediol monovinyl ether, polytetrahydrofuran monovinyl ether,tetraethylene glycol monovinyl ether, trimethylolpropane divinyl etherand aminopropyl vinyl ether.

Adducts can be formed, for example, by reacting the vinyl ethercompounds containing a hydroxyl group or amino group with an excess of adiisocyanate, followed by the reaction of thatfree-isocyanate-group-containing adduct with the free hydroxyl groups ofthe alkyd resin. Preferably, a process is used in which first the freehydroxyl groups of the alkyd resin react with an excess of apolyisocyanate, and then the free isocyanate groups react with anamino-group- or hydroxyl-group-containing vinyl ether compound. Insteadof a diisocyanate, it is also possible to use a diester.Transesterification of the hydroxyl groups present in the alkyd resinwith an excess of the diester, followed by transesterification ortransamidation of the remaining ester groups with hydroxy-functionalvinyl ether compounds or amino-functional vinyl ether compounds,respectively, yields vinyl-ether-functional alkyd resins. It is alsopossible to incorporate (meth)acrylate groups into the alkyd resinduring preparation of the alkyd resin, by carrying out the preparationin the presence of a hydroxy-functional (meth)acrylate ester, such ashydroxyethyl methacrylate (HEMA), and then reacting the thusfunctionalised alkyd resin by means of a Michael reaction with avinyl-ether-group-containing compound and aprimary-amino-group-containing compound, followed by reaction with e.g.an isocyanate compound, in order to obtain a non-basic nitrogen atom.

An example of such a reaction is described, for example, in WO 99/47617.Esterification of ricinine fatty acid with dipentaerythritol, followedby transesterification of the free hydroxyl groups with diethyl malonateand 4-hydroxybutyl vinyl ether in a suitable ratio, yields avinyl-ether-functional alkyd resin suitable for use as component (a1).

For the preparation of acetal-functional alkyd resins, use is generallymade of dialkyl acetal functionalised with an amino group. Examples ofsuitable acetal compounds include 4-aminobutyraldehyde dimethyl acetaland 4-aminobutyraldehyde diethyl acetal. The alkyd resin is modified bythe addition of the aminoacetal monomer to an alkyd resin functionalisedwith isocyanate groups, with ester groups of a low-boiling alcohol orwith (meth)acrylate groups. The resulting dialkyl-acetal-modified alkydresin can be incorporated into the coating composition having a highsolids content and low viscosity. The preparation of acetal-functionalalkyd resins can also be carried out by reacting hydroxyacetal with thecarboxyl groups of the alkyd resin or by reacting a diisocyanate ordiester compound with the hydroxyl groups of the alkyd resin.

An example of this preparative method is described in WO 99/47617, forexample the esterification of a hydroxy-functional alkyd resin withdiethyl malonate, followed by transamidation of the free ester groupwith 4-aminobutyraldehyde dimethyl acetal in a suitable ratio. Theresulting acetal-modified alkyd resin is suitable as component (a1).

For the incorporation of alkoxysilane groups into the alkyd resin, useis made of a siloxane compound having one or more reactive group(s)which are subsequently reacted with one or more of the constituentsmaking up the alkyd resin. These are, for example, alkoxy-silanes of theformula: (E)_(a)-Si(R₁₀)_(b)(R₂₀)_(c), wherein

-   R₁₀ is alkoxy or oxyalkylenealkoxy or, when E is hydrogen, R₁₀ is    halogen,-   R₂₀ is an aliphatic, cycloaliphatic or aromatic group, and E is    hydrogen or an alkyl group substituted by an amino, isocyanate,    mercapto or epoxy group; a is from 1 to 3, b is from 1 to 3, c is    from 0 to 2, and a+b+c=4.-   R₁₀ is preferably an alkoxy group having from 1 to 4 carbon atoms in    the alkoxy group, and-   R₂₀ is preferably a group having not more than 18 carbon atoms.

Examples of suitable siloxane compounds are3-aminopropyl-triethoxysilane, polyglycol-ether-modified aminosilane,3-aminopropyl-trimethoxysilane, 3-aminopropyltris-methoxy-ethoxyethoxysilane, 3-aminopropyl-methyl-diethoxysilane,N-2-aminoethyl-3-aminopropyl-trimethoxy-silane,N-2-aminoethyl-3-aminopropyl-methyldimethoxy-silane,N-methyl-3-aminopropyl-trimethoxysilane, 3-ureidopropyl-triethoxysilane,3,4,5-dihydroimidazol-1-yl-propyltriethoxysilane,3-methacryloxypropyl-trimethoxysilane,3-glycidyloxypropyl-trimethoxysilane, 3-mercaptopropyl-trimethoxysilaneand 3-mercaptopropyl-methyl-dimethoxysilane, triethoxysilane,diethoxymethylsilane, dimethoxymethylsilane, tri-methoxysilane,trichlorosilane, triiodosilane, tribromosilane, dichloromethylsilane anddibromomethylsilane.

The alkyd resin can be modified, for example, by the insertion of anamino-group-modified alkoxysilane into an alkyd resin modified with apolyisocyanate or a polyester of a low-boiling alcohol.Hydride-functional alkoxysilanes can be bonded directly to the alkyd,i.e. without modification with a binding molecule such as a diisocyanateor diester, by adding a compound containing a silylhydride group to anethylenically unsaturated group in the alkyd resin. That addition iscatalysed by a transition metal. In that process, use is preferably madeof a halogenated silylhydride and, in order to terminate the additionreaction, conversion into an alkoxysilane compound with a low-boilingalcohol. The addition reaction is advantageously carried out in theabsence of sterically hindering groups and proceeds in optimum mannerwhen the ethylenically unsaturated groups are terminal groups, as is thecase, for example, with esters of 10-undecenecarboxylic acid.

Examples of the preparation of alkoxysiloxane-modified alkyd resins aredescribed in WO 99/47617. Esterification of a hydroxy-functional alkydresin with diethyl malonate, followed by transamidation of the freeester group with 3-aminopropyltriethoxysilane in a suitable ratio yieldsan alkoxysilane-modified alkyd resin. Hydroxy-modified alkyd resin canalso be reacted with an excess of isophorone diisocyanate, followed byreaction of the free isocyanate groups with3-aminopropyltriethoxysilane. Both alkoxysiloxane-modified alkyd resinsobtained by the processes described are suitable for use in component(a1).

When free-radically polymerisable components are added to theformulation according to the invention, it may be advantageous to addalso a suitable free-radical photoinitiator or a mixture of suchphotoinitiators, e.g. benzophenone and derivatives thereof, ESACURE TZT®available from Lamberti, a mixture of 2,4,6-trimethylbenzophenone and4-methylbenzophenone, Darocur®BP, benzophenone, 4-methyl benzophenone,2,4,6-trimethylbenzophenone, 3-methyl-4′-phenyl-benzophenone,2,4,6-trimethyl-4′-phenyl-benzophenone, etc., acetophenone andderivatives thereof, e.g. 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE®184) or IRGACURE®500 (a mixture of IRGACURE®184 with benzophenone); or2-hydroxy-2-methyl-1-phenyl-propanone (DAROCUR® 1173),2-hydroxy-1-[3-[4-(2-hydroxy-2-methyl-propionyl)-phenyl]-1,1,3-trimethyl-indan-5-yl]-2-methyl-propan-1-one,4-aroyl-1,3-dioxolane, α-hydroxy- or α-amino-acetophenone, such as, forexample, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one(IRGACURE®907),2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1(IRGACURE®369),2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one(IRGACURE®379),1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one(IRGACURE®2959), 2,2-dimethoxy-1,2-diphenylethan-1-one (IRGACURE®651),2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one(IRGACURE® 127),2-benzyl-1-(3,4-dimethoxy-phenyl)-2-dimethylamino-butan-1-one,2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-phenoxy]-phenyl}-2-methyl-propan-1-one,ESACURE®KIP provided by F. Lamberti,2-hydroxy-1-{1-[4-(2-hydroxy-2-methyl-propionyl)-phenyl]-1,3,3-trimethyl-indan-5-yl}-2-methyl-propan-1-one;benzoin alkyl ethers and benzil ketal, such as, for example, benzildimethyl ketal, phenyl glyoxalate and derivatives thereof, e.g.oxo-phenyl-acetic acid 2-[2-(2-oxo-2-phenyl-acetoxy)-ethoxy]-ethyl ester(IRGACURE®754), mono- or bis-acylphosphine oxide, such as, for example,(2,4,6-trimethyl-benzoyl)-phenyl-phosphine oxide (DAROCUR®TPO),bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethyl-pent-1-yl)phosphine oxide,bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide (IRGACURE®819) orbis(2,4,6-trimethylbenzoyl)-(2,4-dipentyloxyphenyl)phosphine oxide.

The DAROCUR and IRGACURE compounds are available from Ciba SpecialtyChemicals.

Other additional components can be, for example, hydroxy-functionalcomponents, such as alcohols, polyester polyols, polyether polyols,hydroxy-group-containing polyurethanes, castor oil, etc. Examplesthereof include aliphatic and cycloaliphatic polyols, such as alkylenediols having preferably from 2 to 12 carbon atoms, e.g. ethylene glycol,1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol,hexanediol, octanediol, dodecanediol, diethylene glycol, triethyleneglycol, polyethylene glycols having molecular weights of preferably from200 to 1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-di-hydroxymethylcyclohexane, glycerol, tris(β-hydroxy-ethyl)amine,trimethylolethane, tri-methylolpropane, pentaerythritol,dipentaerythritol and sorbitol. The polyols can be partially or fullyesterified by one or by different unsaturated carboxylic acids, it beingpossible for the free hydroxyl groups in partial esters to have beenmodified, e.g. etherified, or esterified by other carboxylic acids.Examples of esters include: trimethylolpropane triacrylate,trimethylolethane triacrylate, trimethylolpropane trimethacrylate,trimethylolethane trimeth-acrylate, tetramethylene glycoldimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycoldiacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate,pentaerythritol tetraacrylate, dipentaerythritol diacrylate,dipentaerythritol triacrylate, dipentaerythritol tetraacrylate,dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,tripentaerythritol octaacrylate, pentaerythritol dimethacrylate,pentaerythritol trimethacrylate, dipenta-erythritol dimethacrylate,dipentaerythritol tetramethacrylate, tripentaerythritoloctamethacrylate, pentaerythritol diitaconate, dipentaerythritoltrisitaconate, dipentaerythritol pentaitaconate, dipentaerythritolhexaitaconate, ethylene glycol diacrylate, 1,3-butanediol diacrylate,1,3-butanediol dimethacrylate, 1,4-butanediol diitaconate, sorbitoltriacrylate, sorbitol tetraacrylate, pentaerythritol-modifiedtriacrylate, sorbitol tetramethacrylate, sorbitol pentaacrylate,sorbitol hexaacrylate, oligoester acrylates and methacrylates, glyceroldi- and tri-acrylate, 1,4-cyclohexane diacrylate, bisacrylates andbismethacrylates of polyethylene glycol having a molecular weight offrom 200 to 1500, or mixtures thereof.

The sulphonium salt compounds of formula I can also be used, forexample, as photoactivatable hardeners for siloxane-group-containingresins. Those resins can, for example, either undergo self-condensationby way of acid-catalysed hydrolysis or can be crosslinked with a secondresin component, such as, for example, a polyfunctional alcohol, ahydroxygroup-containing acrylic or polyester resin, a partiallyhydrolysed polyvinylacetal or a polyvinyl alcohol. That type ofpolycondensation of polysiloxanes is described, for example, in J. J.Lebrun, H. Pode, Comprehensive Polymer Science Vol. 5, page 593,Pergamon Press, Oxford, 1989.

Examples of compounds whose solubility increases in a developer underthe action of acid, i.e., component (a2) include oligomers, polymers andcopolymers that can be obtained by co-polymerisation of, for example,the following monomers: non-cyclic or cyclic secondary and tertiaryalkyl (meth)acrylates, such as tert-butyl acrylate, tert-butylmethacrylate, 3-oxocyclohexyl (meth)acrylate, tetrahydropyranyl(meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, cyclohexyl(meth)acrylate, norbornyl (meth)acrylate, isobornyl methacrylate,5-norbornene-2-tert-butyl ester, 8-ethyl-8-tricyclodecanyl(meth)acrylate, (2-tetrahydropyranyl)oxy-norbornylalcohol acrylates,(2-tetrahydropyranyl)oxymethyltricyclododecanemethanol methacrylates,trimethylsilylmethyl (meth)acrylates,(2-tetrahydropyranyl)oxynorbornylalcohol acrylates,(2-tetrahydropyranyl)oxymethyltricyclododecanemethanol methacrylates,trimethylsilylmethyl (meth)acrylate,o-/m-/p-(3-oxocyclohexyloxy)styrene,o-/m-/p-(1-methyl-1-phenylethoxy)styrene,o-/m-/p-tetrahydropyranyloxystyrene, o-1m-1p-adamantyloxystyrene,o-/m-/p-cyclohexyloxystyrene, o-/m-/p-norbornyloxystyrene, non-cyclic orcyclic alkoxycarbonylstyrenes, such aso-/m-/p-tert-butoxycarbonylstyrene,o-1m-1p-(3-oxocyclohexyloxycarbonyl)styrene,o-/m-/p-(1-methyl-1-phenylethoxycarbonyl)styrene,o-/m/p-tetrahydropyranyloxycarbonylstyrene,o-/m-/p-adamantyloxycarbonylstyrene,o-1m-1p-cyclohexyloxycarbonylstyrene,o-/m-/p-norbornyloxycarbonylstyrene, non-cyclic or cyclicalkoxycarbonyloxystyrenes, such aso-/m-/p-tert-butoxycarbonyloxystyrene,o-1m-1p-(3-oxocyclohexyloxycarbonyloxy)styrene,o-/m-/p-(1-methyl-1-phenylethoxycarbonyloxy)styrene,o-/m-/p-tetrahydropyranyloxycarbonyloxystyrene,o-/m-/p-adamantyloxycarbonyloxystyrene,o-/m-/p-cyclohexyloxycarbonyloxystyrene,o-/m-/p-norbornyloxycarbonyloxystyrene, non-cyclic or cyclicalkoxycarbonylalkoxystyrenes, such aso-/m-/p-butoxycarbonylmethoxystyrene,p-tert-butoxycarbonylmethoxystyrene,o-/m-/p-(3-oxocyclohexyloxycarbonylmethoxy)styrene,o-/m-/p-(1-methyl-1-phenylethoxycarbonylmethoxy)styrene,o-1m-1p-tetrahydropyranyloxycarbonyl methoxystyrene,o-/m-/p-adamantyloxycarbonylmethoxystyrene,o-/m-/p-cyclohexyloxycarbonylmethoxystyrene,o-1m-1p-norbornyloxycarbonylmethoxystyrene, trimethylsiloxystyrene,dimethyl(butyl)siloxystyrene, unsaturated alkyl acetates, such asisopropenyl acetate and derivatives thereof, 5-norbornenyl-2-tert-butylester; also monomers that carry acid-labile groups having low activationenergy, such as, for example, p- or m-(1-methoxy-1-methylethoxy)styrene,p- or m-(1-methoxy-1-methylethoxy)methylstyrene, p- orm-(1-methoxy-1-methylpropoxy)styrene, p- orm-(1-methoxy-1-methylpropoxy)methylstyrene, p- orm-(1-methoxyethoxy)styrene, p- or m-(1-methoxyethoxy)methylstyrene, p-or m-(1-ethoxy-1-methylethoxy)styrenes, p- orm-(1-ethoxy-1-methylethoxy)methylstyrene, p- orm-(1-ethoxy-1-methylpropoxy)styrene, p- orm-(1-ethoxy-1-methylpropoxy)methylstyrene, p- orm-(1-ethoxyethoxy)styrene, p- or m-(1-ethoxyethoxy)methylstyrene,p-(1-ethoxyphenylethoxy)styrene, p- orm-(1-n-propoxy-1-methylethoxy)-styrene, p- orm-(1-n-propoxy-1-methylethoxy)methylstyrene, p- orm-(1-n-propoxyethoxy)styrene, p- or m-(1-n-propoxyethoxy)methylstyrene,p- or m-(1-isopropoxy-1-methylethoxy)styrene, p- orm-(1-isopropoxy-1-methylethoxy)methylstyrene, p- orm-(1-isopropoxyethoxy)styrene, p- orm-(1-isopropoxyethoxy)methylstyrene, p- orm-(1-isopropoxy-1-methyl-propoxy)styrene, p- orm-(1-isopropoxy-1-methylpropoxy)-methylstyrene, p- orm-(1-iso-propoxypropoxy)styrene, p- orm-(1-isopropoxypropoxy)-methylstyrene, p- orm-(1-n-butoxy-1-methylethoxy)styrene, p- or m-(1-n-butoxyethoxy)styrene,p- or m-(1-isobutoxy-1-methyl-ethoxy)styrene, p- orm-(1-tert-butoxy-1-methylethoxy)styrene, p- orm-(1-n-pentyloxy-1-methylethoxy)styrene, p- orm-(1-isoamyloxy-1-methylethoxy)styrene, p- orm-(1-n-hexyloxy-1-methylethoxy)styrene, p- orm-(1-cyclohexyloxy-1-methylethoxy)styrene, p- orm-(1-trimethylsilyloxy-1-methylethoxy)styrene, p- orm-(1-trimethylsilyloxy-1-methylethoxy)-methylstyrene, p- orm-(1-benzyloxy-1-methylethoxy)styrene, p- orm-(1-benzyloxy-1-methylethoxy)methylstyrene, p- orm-(1-methoxy-1-methylethoxy)styrene, p- orm-(1-methoxy-1-methylethoxy)-methylstyrene, p- orm-(1-trimethylsilyloxy-1-methylethoxy)-styrene, p- orm-(1-trimethylsilyloxy-1-methylethoxy)methylstyrene. Further examples ofpolymers having alkoxyalkyl ester acid-labile groups can be found inU.S. Pat. No. 5,225,316 and EP 829766. Examples of polymers havingacetal protecting groups are described, for example, in U.S. Pat. No.5,670,299, EP 780 732, U.S. Pat. Nos. 5,627,006, 5,558,976, 5,558,971,5,468,589, EP 704762, EP 762206, EP 342498, EP 553737 and in ACS Symp.Ser. 614, Microelectronics Technology, pp. 35-55 (1995), J. PhotopolymerSci. Technol. Vol. 10, No. 4 (1997), pp. 571-578, J. Photopolymer Sci.Technol. Vol. 12, no. 4 (1999) pp. 591-599 and in “Proceedings of SPIE”,Advances in Resist Technology and Processing XVII, Vol. 3999, Part One,pp. 579-590, 28. Feb.-1. Mar. 2000. The polymers suitable in thecomposition according to the invention are not, however, limitedthereto.

The monomers having an acid-labile group can, where appropriate, also beco-polymerised with other free-radically polymerisable monomers that donot carry acid-labile groups, such as, for example, styrene,acrylonitrile, methyl (meth)acrylate, (meth)acrylic acid,4-hydroxystyrene, 4-acetoxystyrene, 4-methoxystyrene,4-vinylcyclohexanol, norbornene, ethylnorbornene and maleic acidanhydride, in order to establish specific solubility properties andadhesive properties. Alternatively, the acid-labile groups can beintroduced only subsequently in a polymer-analogous reaction. It is alsoknown to the person skilled in the art that the prepolymer can bemodified in targeted manner before such a polymer-analogous reaction,for example by partial hydrogenation, partial alkylation, partialacetylation. That is to say, that the polymer having acid-labile groupsdoes not, in every case, have to be synthesised from monomers bycopolymerisation.

It is also possible to introduce acid-labile crosslinking, as described,for example, in H.-T. Schacht, P. Falcigno, N. Muenzel, R. Schulz and A.Medina, ACS Symp. Ser. 706 (Micro- and Nanopatterning Polymers), pp.78-94, 1997; H.-T. Schacht, N. Muenzel, P. Falcigno, H. Holzwarth and J.Schneider, J. Photopolymer Science and Technology, Vol. 9, (1996),573-586. Such acid-crosslinked systems are preferred in resistapplications from the standpoint of heat stability. Such acid-labilecrosslinking can also be obtained by the reaction ofphenol-group-containing polymers, such as, for example, 4-hydroxystyreneco-polymers, with di- and poly-functional vinyl ethers.

Other examples of component (a2) that increase their solubility in analkaline developer upon reaction with acid are monomeric compounds, suchas, for example, carboxylic acids and phenol-group-containing compounds,in which the carboxylic acid group or phenolic OH group, respectively,has been blocked by acid-labile protecting groups. Such acid-labileblocking can be effected, for example, by conversion of the carboxylgroup into a tert-butyl ester group, a 2-methyl-2-adamantyl ester group,an 8-ethyl-8-tricyclodecanyl ester group, a tetrahydropyranyl estergroup or some other acid-cleavable ester group. Phenolic OH groups canbe blocked according to known processes by conversion, e.g. intoacid-cleavable tert-butylcarbonate groups, silyl ethers, acetal groupsand ketal groups.

The invention relates also to a radiation-sensitive composition whereincomponent (a2) is at least one compound selected from the group ofcycloaliphatic copolymers, 4-hydroxy-phenyl-group-containing copolymers,maleic acid anhydride-containing copolymers and acrylic acid-, acrylicacid ester- and methacrylic acid ester-containing copolymers, with theproviso that those copolymers carry functional groups that increase thesolubility of the polymer in an alkaline developer after reaction withan acid.

In the compositions according to the invention, the photoinitiator (b)is advantageously used in an amount of from 0.05% to 15%, e.g. from 0.5%to 10%, preferably from 1% to 5%, based on the composition.

The compositions according to the invention can be used in numerousapplications, for example in cationically radiation-curable printinginks, in cationically radiation-curable coating compounds which may ormay not be pigmented, in cationically radiation-curable adhesives,coatings and mouldings, including glass fibre-reinforced and carbonfibre-reinforced composites and inner and outer layers of printedcircuit boards.

The compositions according to the invention include also adhesives, asused, for example, for adhesive bonding (DVD bonding) in the manufactureof digital versatile disks (DVD) and as described, for example, in: WO99/66506, WO 99/63017, JP 11241055 A2 Heisei, JP 11181391 A2 Heisei, WO98/31765, and also as radiation-curable laminating adhesives forflexible packaging (see, e.g., U.S. Pat. No. 5,328,940), opticaladhesives (e.g. German Patent Application DD 225985) andpressure-sensitive adhesives (e.g. U.S. Pat. No. 4,988,741 and EP115870).

The compositions according to the invention are advantageously usedwhere there is a need for hard coatings, adhesive bonds orphotopolymerised dimensionally stable three-dimensional mouldings (e.g.for rapid prototyping) having good adhesion to paper, glass, metal,silicon, polycarbonate, acrylate polymers and other polymer substrates,and that exhibit only slight shrinkage during curing.

Depending on the kind of application of the compounds of formula Iaccording to the present invention it may be advantageous to addappropriate further additives, sensitzers and/or photoinitiators. Suchadditives, sensitizers and photoinitiators are customary in the art andknown to the person skilled in the art.

Preference therefore is also given to a composition as described abovethat comprises in addition to components (a1) or (a2) and (b),additional additives (c) and/or sensitiser compounds (d) and optionallyfurther photoinitiators (e).

The photopolymerisable mixtures can comprise various additives (c) inaddition to the photoinitiator. Examples thereof include thermalinhibitors, light stabilisers, optical brighteners, fillers andpigments, as well as white and coloured pigments, dyes, antistatics,adhesion promoters, wetting agents, flow auxiliaries, lubricants, waxes,anti-adhesive agents, dispersants, emulsifiers, anti-oxidants; fillers,e.g. talcum, gypsum, silicic acid, rutile, carbon black, zinc oxide,iron oxides; reaction accelerators, thickeners, matting agents,antifoams, and other adjuvants customary, for example, in lacquer andcoating technology.

The formulations can also comprise dyes and/or white or colouredpigments as additional additives (c). Depending upon the intended use,it is possible to use both inorganic and organic pigments. Suchadditives are known to the person skilled in the art; some examplesthereof are titanium dioxide pigments, for example of the rutile oranatase type, carbon black, zinc oxide, such as zinc white, iron oxides,such as iron oxide yellow, iron oxide red, chromium yellow, chromiumgreen, nickel titanium yellow, ultramarine blue, cobalt blue, bismuthvanadate, cadmium yellow and cadmium red. Examples of organic pigmentsare mono- or bis-azo pigments, and metal complexes thereof,phthalocyanine pigments, polycyclic pigments, such as, for example,perylene, anthraquinone, thioindigo, quinacridone and triphenylmethanepigments, and diketo-pyrrolo-pyrrole, isoindolinone, e.g.tetrachloro-isoindolinone, isoindoline, dioxazine, benzimidazolone andquinophthalone pigments.

The pigments can be used individually or in admixture in theformulations. Depending upon the intended use, the pigments are added tothe formulations in amounts customary in the art, for example in anamount of from 1 to 60% by weight, or from 10 to 30% by weight, based onthe total weight.

The formulations may, for example, also comprise organic dyes of a widevariety of classes. Examples thereof include azo dyes, methine dyes,anthraquinone dyes and metal complex dyes. Customary concentrations are,for example, from 0.1 to 20%, especially from 1 to 5%, based on thetotal weight.

The pigments, latent pigments or dyes or differently coloured precursorsof such pigments and dyes that are added may be so selected that theyundergo a colour change in the presence of the acid formed from theiodonium salt as a result of irradiation. Such compositions then show,by the colour change, that they have been irradiated and can be used,for example, as irradiation dose indicators, e.g. for UV radiation,electron beams, X-rays, etc.

The choice of additives will depend upon the field of use in questionand upon the properties desired for that field. The additives (c)described above are customary in the art and are accordingly used inamounts customary in the art.

The compositions according to the present invention as component (c)also may comprise a stabilizer for the compounds of the formula I, e.g.from the hindered nitroxyl or phosphite type as are for exampledescribed as stabilizers for iodonium salts in WO 05/070989.

Examples for said stabilizer compounds are organic phosphorusstabilizers as disclosed for example in U.S. Pat. No. 6,444,733, thedisclosure of which is hereby incorporated by reference. Organicphosphorus stabilizers are known and many are commercially available.Other examples for said stabilizer compounds are hindered nitroxylstabilizers, or hindered nitroxides, as are well known in the art andare disclosed for example in U.S. Pat. No. 6,337,426 and, U.S. Pat. No.5,254,760, the relevant disclosures of which are hereby incorporated byreference. Other suitable stabilizers (c) for the sulphonium salts ofthe formula I are for example disclosed in WO 99/35188. Examples aretertiary and sterically hindered amines, such as the TINUVIN® products,provided by Ciba Specialty Chemicals, in particular TINUVIN® 144 andTINUVIN® 292. Other possibilities for stabilization of the cationicformulations are e.g. disclosed in EP Patent Application No. 06122783.1,the disclosure is incorporated herein by reference.

Acceleration of the photopolymerisation can also be effected by addingas further additives (d) photosensitisers that shift or broaden thespectral sensitivity. These are especially aromatic carbonyl compounds,such as, for example, benzophenone, thioxanthone, and especially alsoisopropylthioxanthone, phenothiazine derivatives, anthraquinone and3-acylcoumarin derivatives, terphenyls, styryl ketones, and3-(aroylmethylene)-thiazolines, camphorquinone, and also eosin,rhodamine and erythrosin dyes, and anthracene derivatives, such as, forexample, 9-methylanthracene, 9,10-dimethylanthracene,9,10-diethoxyanthracene, 9,10-dibutyloxyanthracene, 9-methoxyanthracene,9-anthracenemethanol, especially 9,10-dimethoxy-2-ethyl-anthracene,9,10-dibutyloxyanthracene and 9,10-diethoxyanthracene. Further suitablephotosensitisers are mentioned, for example, in WO 98/47046. Subject ofthe invention also are radiation-sensitive compositions as describedabove, additionally to components (a1) or (a2) and (b) comprising atleast one sensitizer compound (d), in particular benzophenone,thioxanthone, anthracene or derivatives thereof.

Further examples of suitable photosensitisers (d) are disclosed in WO06/008251, page 36, line 30 to page 38, line 8, the disclosure of whichis hereby incorporated by reference.

It is also possible to use electron donor compounds, such as, forexample, alkyl- and arylamine donor compounds, in the composition. Suchcompounds are, for example, 4-di-methylaminobenzoic acid, ethyl4-dimethylaminobenzoate, 3-dimethylaminobenzoic acid,4-dimethylaminobenzoin, 4-dimethylaminobenzaldehyde,4-dimethylaminobenzonitrile and 1,2,4-trimethoxybenzene. Such donorcompounds are preferably used in a concentration of from 0.01 to 5%,especially in a concentration of from 0.05 to 0.50%, based on theformulation.

The sensitisers (d) described above are customary in the art and areaccordingly used in amounts customary in the art, preferably in aconcentration of from 0.05 to 5%, especially in a concentration of from0.1 to 2%, based on the composition.

The compositions according to the invention may additionally comprisefurther photo-initiators (e), such as, for example, cationicphotoinitiators, photo acid-formers and free-radical photoinitiators asco-initiators in amounts of from 0.01 to 15%, preferably from 0.1 to 5%.

Examples of cationic photoinitiators and acid-formers are phosphoniumsalts, diazonium salts, pyridinium salts, iodonium salts, such as forexample tolylcumyliodonium tetrakis(pentafluorophenyl)borate,4-[(2-hydroxy-tetradecyloxy)phenyl]phenyliodonium hexafluoroantimonateor hexafluorophosphate (SarCat® CD 1012; Sartomer), tolylcumyliodoniumhexafluorophosphate, 4-isobutylphenyl-4′-methylphenyliodoniumhexafluorophosphate (IRGACURE®250, Ciba Specialty Chemicals),4-octyloxyphenyl-phenyliodonium hexafluorophosphate orhexafluoroantimonate, bis(dodecylphenyl)iodonium hexafluoroantimonate orhexafluorophosphate, bis(4-methylphenyl)iodonium hexafluorophosphate,bis(4-methoxyphenyl)iodonium hexafluorophosphate,4-methylphenyl-4′-ethoxyphenyliodonium hexafluorophosphate,4-methylphenyl-4′-dodecylphenyliodonium hexafluorophosphate,4-methylphenyl-4′-phenoxyphenyliodonium hexafluorophosphate. Of all theiodonium salts mentioned, compounds with other anions are, of course,also suitable; further sulphonium salts, obtainable, for example, underthe trade names CYRACURE® UVI-6990, CYRACURE® UVI-6974 (Union Carbide),DEGACURE® KI 85 (Degussa), SP-55, SP-150, SP-170 (Asahi Denka), GE UVE1014 (General Electric), SarCat® KI-85 (=triarylsulphoniumhexafluorophosphate; Sartomer), SarCat® CD 1010 (=mixedtriarylsulphonium hexafluoroantimonate; Sartomer); SarCat® CD 1011(=mixed triarylsulphonium hexafluorophosphate; Sartomer); ferroceniumsalts, e.g. (η⁶-isopropylbenzene)(η⁵-cyclopentadienyl)-iron-IIhexafluorophosphate, nitrobenzylsulphonates, alkyl- andaryl-N-sulphonyloxyimides and further known alkylsulphonic acid esters,haloalkylsulphonic acid esters, 1,2-disulphones, oxime sulphonates,benzoin tosylate,tolylsulphonyloxy-2-hydroxy-2-methyl-1-phenyl-1-propanone and furtherknown betaketosulphones, beta-sulphonylsulphones,bis(alkylsulphonyl)diazomethane,bis(4-tert-butylphenyl-sulphonyl)-diazomethane,benzoyl-tosyl-diazomethane, iminosulphonates and imidosulphonates andtrichloromethyl-s-triazines and other haloalkyl-group-containingcompounds. Examples of further suitable additional photolatent acids(b1) include the examples of cationic photoinitiators and acid-formersas given in WO 04/074242, page 38, line 10 to page 41, line 14, as wellas the compounds disclosed in the examples of WO 04/074242, the relevantdisclosure of which is incorporated herein by reference.

Examples of free-radical photoinitiators as co-initiators are compoundsas described above.

The compositions according to the invention may be used for a variety ofpurposes, for example as printing inks, such as screen-printing inks,flexo printing inks or offset printing inks, as clear lacquer, ascoloured surface-coating compositions, as white surface-coatingcompositions, e.g. for wood or metal, as powder coating compositions, aspaint, inter alia for paper, wood, metal or plastics, asdaylight-curable paint for marking structures and roads, forphotographic reproduction processes, for holographic recordingmaterials, for image-recording processes or for the production ofprinting plates that are to be developed with organic solvents or usingaqueous-alkaline media, in the production of masks for screen-printing,as dental filling compounds, as radiation-curable adhesives, aspressure-sensitive adhesives, as anti-adhesive coatings, as laminatingresins, as photoresists, e.g. galvano-resists, etch resists or permanentresists, liquid films and dry films, as photostructurable dielectrics,and as solder masks for electronic circuits, as resists in themanufacture of colour filters for any type of screen or for producingstructures in the manufacture of plasma displays and electroluminescentdisplays, in the manufacture of optical switches, optical gratings(interference gratings), in the coating or sealing of electroniccomponents, e.g. as electroinsulating compounds, or as coatings foroptical fibres, for coil coating, as indicator systems for UV radiation,X-rays and electron beams, and in the manufacture of three-dimensionalarticles, e.g. for stereolithography and for composites, e.g. forcomposites reinforced with glass or carbon or graphite fibres. Thecompositions are also suitable for the manufacture of optical lenses,e.g. contact lenses or Fresnel lenses, and also in the manufacture ofmedical apparatus, aids or implants.

The photocurable compositions according to the invention are suitable,for example, as coating materials for all kinds of substrates, forexample wood, textiles, paper, ceramics, glass, marble, plastics, suchas polyester, polyethylene terephthalate, polyolefins or celluloseacetate, especially in the form of films, and metals, such as Al, Cu,Ni, Fe, Zn, Mg or Co and GaAs, Si or SiO₂, to which a coating is to beapplied or an image is to be applied by image-wise exposure, or to whicha structured resist layer is to be applied.

The coating of the substrates can be effected by applying a liquidcomposition, a solution or suspension to the substrate. The choice ofsolvent in a solution and the concentration are governed chiefly by thenature of the composition and by the coating method. The solvent shouldbe inert, that is to say it should not enter into any chemical reactionwith the components and it should be capable of being removed again upondrying after the coating operation.

Examples of suitable solvents are ketones, ethers and esters, such asmethyl ethyl ketone, isobutyl methyl ketone, cyclopentanone,cyclohexanone, 2-heptanone, methyl amyl ketone, N-methylpyrrolidone,gamma-butyrolactone, dioxane, tetrahydrofuran, 2-methoxyethanol,2-ethoxyethanol, 1-methoxy-2-propanol, 1,2-dimethoxyethane, acetic acidethyl ester, acetic acid n-butyl ester, propylene glycol monomethylether acetate, lactic acid ethyl ester, propylene carbonate and3-ethoxy-propionic acid ethyl ester.

After coating of the substrates, the solvent is generally removed bydrying.

The formulation is applied uniformly to a substrate by known coatingmethods, for example by spin-coating, immersion, knife coating, curtainpouring, brush application or spraying, especially by electrostaticspraying and reverse-roll coating, and by electrophoretic deposition. Itis also possible to apply the photosensitive layer to a temporaryflexible support and then coat the final substrate, e.g. acopper-laminated printed circuit board, by transferring the layer bylamination.

The amount applied (layer thickness) and the type of substrate (layersupport) are dependent upon the desired field of use. The layerthickness range generally includes values from about 0.1 μm to more than100 μm, preferably from 0.5 micrometre to 50 micrometres. In themanufacture of three-dimensional articles, e.g. by stereolithography,the dimensions of the articles that can be obtained are limited only bythe size of the exposure apparatus.

The radiation-sensitive compositions according to the invention areused, for example, as negative resists that have very highphotosensitivity and that can be developed in an aqueous-alkaline mediumwithout swelling. They are suitable as photoresists for electronics,such as galvanoresists, etch resists, and in liquid and dry films,solder resists, as resists in the production of colour filters for anytype of screen, or to form structures in the manufacture of plasmadisplays and electroluminescent displays, in the manufacture of printingplates, e.g. offset printing plates, in the manufacture of printingmoulds for letterpress printing, flatbed printing, intaglio printing,flexo printing or screen-printing moulds, the production of reliefcopies, e.g. for the production of texts in braille, for the productionof stamps, for use in the etching of mouldings or for use as amicroresist in the manufacture of integrated switching circuits. Thecompositions can also be used as photostructurable dielectrics, forencapsulating materials or as an insulating coating in the manufactureof computer chips, printed circuits and other electrical or electroniccomponents. The possible layer supports and processing conditions forthe coated substrates vary accordingly.

The compounds according to the invention are also used in themanufacture of single- or multi-layer materials for image recording orimage reproduction (copies, reprography), which may be monochromatic orpolychromatic. Included therein are materials for holographic storage ofinformation, e.g. for holographic images or 3-dimensional holographicdata storage. Such materials can also be used in colour test systems. Inthat technology it is also possible to use formulations that comprisemicrocapsules and, to produce the image, a thermal step can be carriedout after the exposure step. Such systems and technologies and their useare described, e.g., in U.S. Pat. No. 5,376,459.

For photographic recordings of information there are used, for example,films of polyester, cellulose acetate or plastics-coated papers; foroffset printing moulds there is used specially treated aluminium; forthe production of printed circuits there are used copper-coatedlaminates; and for the production of integrated switching circuits thereare used silicon wafers. The layer thicknesses for photographicmaterials and offset printing moulds are generally from about 0.5 μm to10 μm, and for printed circuits from 1.0 μm to about 100 μm.

The invention relates also to the use of compounds of formula I asradiation-sensitive acid donors in the manufacture of surface-coatingcompositions, printing inks, printing plates, dental compounds,stereolithography resins, adhesives, anti-adhesive coatings, colourfilters, resist materials or image-recording materials.

The invention relates also to a coated substrate that is coated on atleast one surface with a composition according to the invention, and toa method for the production of relief images, wherein a compositionaccording to the invention is applied to a substrate and is then exposedimage-wise.

The expression “image-wise exposure” includes irradiation through a maskthat contains a predetermined pattern, for example a diapositive, ametal mask, a chrome mask on a trans-parent support, exposure by meansof a laser beam that is moved, for example controlled by a computer,over the surface of the coated substrate and in that manner produces animage, and irradiation with computer-controlled electron beams (CTP).Images can also be produced by interference between two beams or images,for example for holographic uses. It is also possible to use liquidcrystal masks that can be actuated pixel by pixel to produce digitalimages, as described, for example, by A. Bertsch, J. Y. Jezequel, J. C.Andre in Journal of Photochemistry and Photobiology A: Chemistry 1997,107, pp. 275-281 and by K.-P. Nicolay in Offset Printing 1997, 6, pp.34-37.

As already mentioned, the compounds of formula I can be used especiallyalso as acid donors in photoresists. Resist systems can be obtained byimage-wise exposure of formulations comprising compounds of formula Iand a subsequent development step. The term “photoresist” is not limitedto the chemically enhanced resists, but includes all resist materials inwhich reactions are initiated by the radiation-chemical production ofacid and that, in a development step, result in a difference insolubility between exposed and non-exposed regions. For example, alsoincluded are resists that can be processed in an aqueous medium, asdescribed, for example, in U.S. Pat. No. 5,998,092 and in SPIE, Vol.3999, pp. 569-578 (2000) as well as resists based on a Pinacolrearrangement, as described, for example, in SPIE, Vol. 3999, pp. 62-73(2000).

Accordingly, the invention relates also to a photoresist that comprisesa compound of formula I as radiation-sensitive acid donor.

A chemically enhanced photoresist is to be understood as being a resistformulation in which the radiation-sensitive component provides acatalytic amount of acid, which in turn catalyses a chemical reaction ofat least one acid-sensitive component of the resist. This results in adifference in the solubility of the irradiated and non-irradiatedportions of the resist. As a result of the catalytic nature of thatprocess, an acid molecule can initiate reactions at many sites becauseit diffuses through the reactive polymer matrix from one reaction siteto the next, provided it is not captured or destroyed by secondaryreactions. Even a low acid concentration is therefore sufficient toobtain large differences in solubility between irradiated andnon-irradiated portions of the resist. It is therefore generallysufficient to add only a small amount of latent acid compound. It isnecessary, however, for the latent acid donors to be chemically andthermally stable until they are being irradiated. It is also necessaryfor the latent catalysts to be readily soluble in the liquid resistformulation and in the solid resist film in order to avoid the formationof particles which would adversely affect the use of the resists inmicroelectronic processing processes.

It will be clear from the above remarks that chemical and thermalstability of the latent acid donor is essential for its use inchemically enhanced photoresists.

The difference in solubility between exposed and non-exposed areas inthe resist, which results from the action of the acid-catalysedreaction, depends upon the other components in the resist. If thecompositions according to the invention comprise components thatincrease the solubility of the composition in the developer afterirradiation and optionally after thermal aftertreatment, then it is apositive photoresist.

The invention accordingly relates also to a positive photoresist.

If, however, the components of the composition lower the solubility inthe developer after irradiation and optionally after thermalaftertreatment, then it is a negative photoresist.

The invention accordingly relates also to a negative photoresist.

An overview of chemically enhanced photoresists can be found, forexample, in: H. Ito, IBM Journal of Research and Development, Vol. 41,No. 1/2, page 69 (1997); H. Ito, SPIE Vol. 3678, page 2 (1999); fornegative resists in: J. M. Shaw et al. IBM Journal of Research andDevelopment, Vol. 41, No. 1/2, page 81 (1997).

Suitable negative and positive, e.g. chemically amplified, resistformulations, in which the compounds of the formula I according to thepresent invention can be employed as photolatent acid donors aredisclosed in WO 04/074242, page 19, last paragraph to page 38, line 7.Said disclosure is hereby incorporated by reference.

It is evident, that also additives (c), customary in resist formulationsmay be added to corresponding formulations comprising a compound of theformula I according to the present invention. Examples of such additivesare used in photoresists in the customary amounts known to a personskilled in the art, and are for example, dyes, pigments, plasticizers,surfactants, flow improvers, wetting agents, adhesion promoters,thixotropic agents, colourants, fillers, solubility accelerators,spectral sensitizers, acid-amplifiers, photosensitizers and organicbasic compounds. Further, solvents and surfactants may be added. Athorough disclosure is given in WO 04/074242, page 41, line 15 to page45, line 4. Said disclosure is hereby incorporated by reference.

To prepare a photoresist, the compositions according to the presentinvention, suitably in a solvent, is applied to a substrate, the solventis evaporated by heating and the coated substrate is exposed toelectromagnetic radiation, e.g. a laser.

After exposure and, if necessary after the thermal treatment, theexposed sites of the composition (in the case of the positive resist) orthe non-exposed sites of the composition (in the case of the negativeresist) are removed using a developer in a manner generally known to aperson skilled in the art. Optionally prior to the development step afurther heating step is performed. A thorough disclosure is given in WO04/074242, page 45, line 5 to page 47, line 8. Said disclosure is herebyincorporated by reference.

Thus, the invention relates also to a method of manufacturing aphotoresist by

-   (1) applying a composition as described above to a substrate;-   (2) heating the composition to a temperature of from 60° C. to 160°    C.;-   (3) carrying out image-wise exposure with light of a wavelength of    from 150 nm to 1500 nm;-   (4) optionally heating the composition to temperatures of from    60° C. to 160° C.; and-   (5) subsequently developing with a solvent or an aqueous alkaline    developer.

The invention relates also to the use of compounds of formula I asdescribed above as photolatent acid donors in the polymerisation orcrosslinking of cationically or acid-catalytically polymerisable orcrosslinkable compounds or to increase the solubility of compounds thatincrease their solubility in a developer under the action of acid, andalso to a method for the photopolymerisation or crosslinking ofcationically or acid-catalytically polymerisable or crosslinkablecompounds under the action of electromagnetic radiation, in which methoda compound of formula I is used as photolatent acid donor.

A further subject of the invention is a method as described above in themanufacture of surface-coating compositions including scratch-resistantcoatings, stain-resistant coatings, anti-fog coatings, stain resistantcoatings, anticorrosion coatings, powder coating compositions, printinginks, non impact printing inks including ink jet printing inksprintingplates, dental compounds including composites, stereolithography resins,adhesives, anti-adhesive coatings (release coatings, especially siliconrelease coatings), conformal coatings, optical fiber coatings, colourfilters, resist materials or image-recording materials includingholography resins.

The composition according to the present invention, comprising acationic photoinitiator of the formula I may also be employed in avacuum deposition process as described in WO 02/064268. That is, thephotoinitiators are suitable to be flash-evaporated vacuum-deposited.Accordingly, in a process for forming a solid poylmeric structure fromflash-evaporated vacuum-deposited cationically curable monomericmaterial, comprising the steps

-   (i) preparing a mixture of a cationically-curable monomer with a    thermally stable, chemically inactive at room temperature, cationic    photoinitiator;-   (ii) flash-evaporating said mixture in a vacuum to produce a vapor;-   (iii) condensing the vapor to produce a film; and-   (iv) exposing said film to a radiation source to produce a polymeric    solid film,    said photoinitiator is of the formula I as described above.

Suitable apparatus for said procedure, as wel as details concerning themonomers are described in WO 02/064268, the teachings of which areincorporated by reference.

The UV irradiation to release the acid is generally effected with lightof a wavelength of from 157 to 600 nm. Suitable radiation is present,for example, in sunlight or light from artificial light sources. A largenumber of widely varying types of light source may be used. Pointsources and also planiform radiators (lamp carpets) are suitable.Examples thereof include: carbon arc lamps, xenon arc lamps, medium-,high- and low-pressure mercury lamps, doped where appropriate with metalhalides (metal halide lamps), microwave-excited metal vapour lamps,excimer lamps, superactinic fluorescent tubes, fluorescent lamps, argonincandescent lamps, flashlamps, photographic flood lights, lightemitting diodes (LED), electron beams and X-rays. Further, exposure to aplasma or corona is suitable as radiation for activating thephotoinitiator compounds according to the present invention. Thedistance between the lamp and the substrate to be exposed can varyaccording to the intended use and the type and strength of the lamp andmay be, for example, from 0 cm to 150 cm, or from 0.5 cm to 150 cm,preferably from 2 cm to 150 cm. Laser light sources, for example excimerlasers, are also suitable. Lasers in the visible range can also be used.

The examples which follow illustrate the invention in more detail. Partsand percentages are, as in the remainder of the description and in theclaims, by weight, unless stated otherwise. Where alkyl radicals havingmore than three carbon atoms are referred to without any mention ofspecific isomers, the n-isomers are meant in each case

EXAMPLE 1 Preparation of

In a 200 ml reactor 1.54 g of thionyl chloride, 10.36 g of aluminiumchloride and 9.62 g of 4-phenoxy-acetophenone [5031-78-7] are slowlyadded to 30 ml of o-dichlorobenzene at room temperature, and thereaction mixture is stirred for 3 hours at room temperature, and thenfor 3 hours at 50° C. The reaction mixture is poured on a water-icemixture and well stirred. The product is extracted with dichloromethaneand purified.

¹H-NMR data (δ ppm, DMSO-d₆): 8.05 6H d, 7.92 6H d, 7.43 6H d, 7.28 6Hd, 2.59 9H s.

EXAMPLE 2 Preparation of

10.8 g of the compound of example 1 is dissolved in 30 ml ofdichloromethane and 14.17 g of potassium hexafluorophosphate isdissolved in 150 ml of water. The two solutions are brought together andare stirred vigorously for 3 hours at room temperature. The phases areseparated and the product is then isolated by evaporating the solvent.The product is purified by column chromatography.

¹H-NMR data (δ ppm, CDCl₃): 8.00 6H d, 7.70 6H d, 7.28 6H d, 7.13 6H d,2.59 9H s.

EXAMPLE 3 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-phenoxybenzophenone [6317-73-3] instead of4-phenoxyacetophenone.

¹H-NMR data (δ ppm, CDCl₃): 8.02 6H d, 7.87 6H d, 7.79 6H d, 7.61 3Hdxd, 7.50 6H dxd, 7.29 6H d, 7.17 6H d.

EXAMPLE 4 Preparation of

The compound is prepared from the compound of example 3 according to themethod as described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 7.88 6H d, 7.80 6H d, 7.71 6H d, 7.60 3Hdxd, 7.51 6H dxd, 7.32 6H d, 7.18 6H d.

EXAMPLE 5 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-phenylthioacetophenone [10169-55-8] instead of4-phenoxyacetophenone.

¹H-NMR data (δ ppm, CDCl₃): 7.98 6H d, 7.78 6H d, 7.57 6H d, 7.35 6H d,2.63 9H s;

EXAMPLE 6 Preparation of

The compound is prepared from the compound of example 5 according to themethod as described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 8.00 6H d, 7.56 6H d, 7.52 6H d, 7.41 6H d,2.63 9H s.

EXAMPLE 7 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-phenylthiobenzophenone [6317-78-8] instead of4-phenoxyacetophenone.

¹H-NMR data (δ ppm, CDCl₃): 7.83-7.77 18H m, 7.64 3H dxd, 7.58 6H d,7.52 6H dxd, 7.41 6H d.

EXAMPLE 8 Preparation of

The compound is prepared from the compound of example 7 according to themethod as described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 7.86 6H d, 7.84 6H d, 7.65 3H dxd, 7.62 6Hd, 7.54 6H d, 7.52 6H dxd, 7.45 6H d.

EXAMPLE 9 Preparation of

The compound is prepared from the compound of example 1 according to themethod as described in example 2 with NaSbF₆ instead of KPF₆.

¹H-NMR data (δ ppm, CDCl₃): 8.03 6H d, 7.65 6H d, 7.31 6H d, 7.16 6H d,2.62 9H s.

EXAMPLE 10 Preparation of

The compound is prepared from the compound of example 1 according to themethod as described in example 2 withlithium[tris(trifluoromethylsulfonyl)methide] instead of KPF₆.

¹H-NMR data (δ ppm, CDCl₃): 8.03 6H d, 7.61 6H d, 7.28 6H d, 7.16 6H d,2.61 9H s.

EXAMPLE 11 Preparation of

The compound is prepared from the compound of example 5 according to themethod as described in example 2 with NaSbF₆ instead of KPF₆.

¹H-NMR data (δ ppm, CDCl₃): 7.98 6H d, 7.56 6H d, 7.52 6H d, 7.41 6H d,2.61 9H s.

EXAMPLE 12 Preparation of

The compound is prepared from the compound of example 5 according to themethod as described in example 2 withlithium[tris(trifluoromethylsulfonyl)methide] instead of KPF₆.

¹H-NMR data (δ ppm, CDCl₃): 8.01 6H d, 7.59 6H d, 7.45 6H d, 7.39 6H d,2.63 9H s.

EXAMPLE 13 Preparation of

The compound is prepared according to the method as described in example1, by employing 1-[4-(phenylthio)phenyl]-1-propanone [96187-78-9]instead of 4-phenoxyacetophenone.

¹H-NMR data (δ ppm, CDCl₃): 7.98 6H d, 7.78 6H d, 7.56 6H d, 7.36 6H d,3.00 6H q, 1.24 9H t;

EXAMPLE 14 Preparation of

The compound is prepared from the compound of example 13 according tothe method described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 8.01 6H d, 7.58 6H d, 7.51 6H d, 7.41 6H d,3.02 6H q, 1.24 9H t.

EXAMPLE 15 Preparation of

The compound is prepared according to the method as described in example1, by employing 1-(4-phenylsulfanyl-phenyl)-propan-1-one [10130-82-2]instead of 4-phenoxyacetophenone.

¹H-NMR data (δ ppm, DMSO-d₆): 7.94 6H d, 7.84 6H d, 7.52 6H d, 7.37 6Hd, 3.49 3H sept., 1.18 18H d.

EXAMPLE 16 Preparation of

The compound is prepared from the compound of example 15 according tothe method described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 8.00 6H d, 7.58 6H d, 7.51 6H d, 7.41 6H d,3.56 3H sept., 1.25 18H d;

EXAMPLE 17 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-pivaloyl-diphenylsulfide (=the compound of example 21)instead of 4-phenoxyacetophenone.

¹H-NMR data (δ ppm, CDCl₃): 7.94 6H d, 7.84 6H d, 7.52 6H d, 7.37 6H d,1.35 27H s.

EXAMPLE 18 Preparation of

The compound is prepared from the compound of example 17 according tothe method described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 7.73 6H d, 7.52 6H d, 7.48 6H d, 7.37 6H d,1.36 27H s.

EXAMPLE 19 Preparation of

The compound is prepared according to the method as described in example1, by employing 1-(4-phenylsulfanyl-phenyl)-octan-1-one [17792-67-5]instead of 4-phenoxyacetophenone.

¹H-NMR data (ppm, CDCl₃): 7.95 6H d, 7.76 6H d, 7.53 6H d, 7.34 6H d,2.94 6H t, 1.76-1.69 6H m, 1.36-1.16 24H m, 0.87 9H t.

EXAMPLE 20 Preparation of

The compound is prepared from the compound of example 19 according tothe method described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 7.99 6H d, 7.57 6H d, 7.53 6H d, 7.40 6H d,2.95 6H t, 1.78-1.69 6H m, 1.36-1.29 24H m, 0.89 9H t;

EXAMPLE 21 Preparation of

26.67 g of aluminum chloride are suspended in 100 ml dichloromethane,and 37.25 g of diphenylsulfide are added. Then 24.12 g of pivalic acidchloride are added slowly at 0° C., and the mixture is stirred for 1hour at a temperature between 0° C. and 5° C. The mixture is poured onice, the phases are separated and the organic phase is dried over MgSO₄.After evaporation of the solvent, the crude product is chromatographedover silica gel and the desired compound is obtained.

¹H-NMR data (δ ppm, CDCl₃): 7.69 2H d, 7.51-7.46 2H m, 7.42-7.36 3H m,7.22 2H d, 1.36 9H s.

EXAMPLE 22 Preparation of

The compound is prepared from the compound of example 5 according to themethod as described in example 2 with NaC₄F₉SO₃ (sodium nonaflate)instead of KPF₆.

¹H-NMR data (δ ppm, CDCl₃): 7.99 6H d, 7.61 6H d, 7.56 6H d, 7.40 6H d,2.63 9H s.

EXAMPLE 23 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-phenoxy-benzoicacidmethylester [21218-94-0] instead of4-phenoxyacetophenone. The product then is directly transformed to thePF₆ salt according to the method as described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 8.08 6H d, 7.70 6H d, 7.27 6H d, 7.12 6H d,3.91 9H s.

EXAMPLE 24 Preparation of

The compound is prepared according to the method as described in example1, by employing 4-phenoxy-benzonitrile [3096-81-9] instead of4-phenoxyacetophenone. The product then is directly transformed to thePF₆ salt according to the method as described in example 2.

¹H-NMR data (δ ppm, CDCl₃): 7.74 6H d, 7.60 6H d, 7.27 6H d, 7.12 6H d.

EXAMPLE 25

A composition is prepared by mixing the following components:

-   -   81.80 parts of 3,4-epoxycyclohexylmethyl carboxylate (CYRACURE®        UVR 6105, provided by Dow Chemical)    -   11.73 parts of 3-ethyl-3-hydroxymethyl-oxetane (CYRACURE® UVR        6000, provided by Dow Chemical)    -   5.92 parts of ε-caprolactane triol (Tone Polyol 301, provided by        Dow Chemical)    -   0.56 parts of a silicon surface additive (Byk 307, provided by        BYK)    -   100.0 parts overprint varnish, felxo ink basic formulation

The compound to be tested is stirred into said formulation, which thenis applied with a 4 μm wire bar onto an aluminum film of 85 μmthickness.

Curing is effected by moving the sample on a conveyor belt under a 1×120W/cm medium pressure mercury lamp (IST) fitted with an aluminumreflector.

The highest speed of the conveyor belt, which is used to cure therespective formulation is a measure for the reactivity of the testedphotoinitiator compound. The results are collected in table 1.

TABLE 1 concentration Cure speed Photoinitiator [%] [m/min] of example 63 170 of example 14 4 200 of example 2 4 200

1. A compound of the formula Ia

L, L₁, L₂, L₃, L₄, L₅, L₆, L₇ and L₈ independently of one another arehydrogen, R₁, OR₁, SR₁, NR₁R₂, halogen, NO₂, CN, NR₁COR₂, COOR₁, OCOR₁,CONR₁R₂, OCOOR₁, OCONR₁R₂, NR₁COOR₂, SO₃H, SO₃M, SOR₁, SO₂R₁ or are COT;and/ or the pairs L₃ and L₅ together are a single bond, CR_(a)R_(b), CO,O, S, NR_(c) or NCOR_(c); provided that L₃ and L₅ together are not asingle bond, when X denotes a single bond; and/or the pairs L₁ and L₃,L₁ and L, L₅ and L₇ together are C₁-C₃alkylene, CR₁═CR₂-CR₃═CR₄,CR₁═CR₂—O, CR₁═CR₂—S, CR₁═CR₂—NR₁, CO—O—CO CONR₁CO, CO-(o-phenylene)-S,CO-(o-phenylene)-S substituted by one or more D, or are C₁-C₃alkyleneinterrupted by O, S, NR₁ or NCOR₁; provided that at least one of L, L₁,L₂, L₃, L₄, L₅, L₆, L₇, L₈is other than hydrogen; T₁ and T₂independently of one another are hydrogen, C₁-C₂₀alkyl,C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₅-C₁₂cycloalkenyl, C₆-C₁₄aryl,C₁-C₂₀alkyl substituted by one or more D, C₂-C₂₀alkyl interrupted by oneor more E, C₂-C₂₀alkyl substituted by one or more D and interrupted byone or more E, C₅-C₁₂cycloalkyl substituted by one or more D,C₂-C₁₂cycloalkyl interrupted by one or more E, C₂-C₁₂cycloalkylsubstituted by one or more D and interrupted by one or more E,C₂-C₂₀alkenyl substituted by one or more D, C₃-C₂₀alkenyl interrupted byone or more E, C₃-C₂₀alkenyl substituted by one or more D andinterrupted by one or more E, C₅-C₁₂cycloalkenyl substituted by one ormore D, C₃-C₁₂cycloalkenyl interrupted by one or more E,C₃-C₁₂cycloalkenyl substituted by one or more D and interrupted by oneor more E, or C₆-C₁₄aryl substituted by one or more D; R₁, R₂, R₃, R₄,R_(a), R_(b) and R_(c) independently of one another have the meaning ofT₁; T denotes T₁ or O-T₂; X is a single bond, CR_(a)R_(b), O, S, NR_(c)or NCOR_(c); D is hydrogen, R₅, OR₅, SR₅, NR₅R₆, halogen, NO₂, CN,O-glycidyl, O-vinyl, O-allyl, COR₅, NR₅COR₆, COOR₅, OCOR₅, CONR₅R₆,OCOOR₅, OCONR₅R₆, NR₅COOR₆, SO₃H or SO₃M; E is O, S, COO, OCO, CO, NR₅,NCOR₅, NR₅CO, CONR₅, OCOO, OCONR₅, NR₅COO, SO₂, SO, CR₅═CR₆ or

R₅ and R₆ independently of one another are hydrogen, C₁-C₁₂alkyl orphenyl; Y is an inorganic or organic anion; and M is an inorganic ororganic cation.
 2. A compound of the formula Ia according to claim 1,wherein L, L₁, L₂, L₃ and L₄ independently of one another are hydrogen,R₁, OR₁, halogen, SO₃H, SO₃M, SOR₁, SO₂R₁, CN, NO₂ or COT; L₅, L₆, L₇and L₈ independently of one another are hydrogen, R₁ or OR₁; providedthat at least one of L, L₁, L₂, L₃, L₄ is SO₃H, SO₃M, SO₂R₁, CN, NO₂ orCOT; T₁ and T₂ independently of one another are hydrogen, C₁-C₂₀alkyl,C₅-C₁₂cycloalkyl, C₂-C₂₀alkenyl, C₆-C₁₄aryl, C₁-C₂₀alkyl substituted byone or more D, C₂-C₂₀alkyl interrupted by one or more E, C₂-C₂₀alkylsubstituted by one or more D and interrupted by one or more E,C₅-C₁₂cycloalkyl substituted by one or more D, C₂-C₁₂cycloalkylinterrupted by one or more E, C₂-C₁₂cycloalkyl substituted by one ormore D and interrupted by one or more E, C₂-C₂₀alkenyl substituted byone or more D, C₃-C₂₀alkenyl interrupted by one or more E, C₃-C₂₀alkenylsubstituted by one or more D and interrupted by one or more E,C₆-C₁₄aryl substituted by one or more D; R₁, R_(a), R_(b) and R_(c)independently of one another have the meaning of T₁; T is T₁ or O—T₂; Xis a single bond, CR_(a)R_(b), O, S, NR_(c) or NCOR_(c); D is hydrogen,R₅, OR₅, SR₅, halogen, NO₂, CN, O-glycidyl, O-vinyl, O-allyl, COR₅,COOR₅ or OCOR₅; E is O, S, COO, OCO, CO or CR₅═CR₆; R₅ and R₆independently of one another are hydrogen, C₁-C₁₂alkyl or phenyl; Y isan inorganic or organic anion; and M is an inorganic or organic cation.3. A compound of the formula Ia according to claim 1, wherein L₁, L₂,L₃, L₄, L₅, L₆, L₇ and L₈ are hydrogen L is COT, COOR₁ or CN; T is T₁;T₁ is C₁-C_(2o)alkyl or C₆-C_(u)aryl; R₁ is C_(r)C₂₀alkyl; X is O or S;Y is halogen or a non-nucleophilic anion, selected from the groupC_(f)F_(2f+1)SO₃ ⁻, C₁-C₂₀-perfluoroalkylsulphonylmethide, (BF₄)⁻,(SbF₆)⁻, (AsF₆)⁻, (PF₆)⁻ and (B(C₆F₅)₄)⁻; and f is an integer from 1 to8.
 4. Process for the preparation of a compound of the formula Ia, byreacting a compound of the formula II,

L, L₁, L₂, L₃, L₄, L₅, L₆, L₇, L₈ and X are as defined in claim 1; withthionylchloride in the presence of a Friedel-Crafts catalyst, optionallyfollowed by an exchange of the anion Y.
 5. A radiation-sensitivecomposition comprising (a1) a cationically or acid-catalyticallypolymerisable or crosslinkable compound or (a2) a compound thatincreases its solubility in a developer under the action of acid; and(b) at least one compound of the formula Ia according to claim
 1. 6. Aradiation-sensitive composition according to claim 5, additionally tocomponents (a1) or (a2) and (b), comprising additional additives (c)and/or sensitiser compounds (d) and optionally further photoinitiators(e).
 7. Surface-coating compositions, powder coating compositions,printing inks, printing plates, dental compounds, stereolithographyresins, adhesives, anti-adhesive coatings, colour filters, resistmaterials or image-recording materials comprising at least one compoundof the formula Ia according to claim
 1. 8. A coated substrate that iscoated on at least one surface with a composition according to claim 5.9. A method for the photopolymerisation or crosslinking of cationicallyor acid-catalytically polymerisable or crosslinkable compounds under theaction of electromagnetic radiation or an electron beam, in which methoda compound of formula Ia according to claim 1 is used as photolatentacid donor.
 10. Method according to claim 9 in the manufacture ofsurface-coating compositions, scratch-resistant coatings,stain-resistant coatings, antifog coatings, anticorrosion coatings,powder coating compositions, printing inks, non impact printing inks,ink jet printing inks, printing plates, dental compounds, composites fordental, composites, stereolithography resins, adhesives, anti-adhesivecoatings, conformal coatings, optical fiber coatings, colour filters,resist materials or image-recording materials, holography resins.